US3140241A - Processes for producing carbonaceous materials - Google Patents

Description

y 7, 1954 J. WORK ETAL 3,140,241

PROCESSES FOR PRODUCING CARBONACEOUS MATERIALS Filed June 18, 1959 2 Sheets-Sheet 1 FIGURE I STOCK w w STORAGE 8 I l 3 GOALS GROUND PARENT COAL i ANTHRACITE THRU LIGNITE GRINDING CATALYZING ZED DRY STAGE NON AGGLOMERATING COAL CARBONIZING CHAR STAGE l VAPORS LIQUOR GAS CALCINING STAGE CALOINATE TAR PITCH COOLING OTHER amosns WHEN NECESSARY BLENDING CURING CURED SHAPES i GAS Inventors 1 JOSIAH WORK ROBERT r JOSEPH 1' COKNG JOHN h. BLAKE COKE SHAPES Afiomeys United States Patent 3,140,241 PROCESSES FOR PRODUCING CARBONACEOUS MATERIALS Josiah Work, Darien, Conn., Robert T. Joseph, Richboro,

Pa., and John H. Blake, Boulder, Colo., assignors to FMC Corporation, a corporation of Delaware Filed June 18, 1959, Ser. No. 821,137 24 Claims. (Cl. 20226) This invention relates to processes for producing physically strong, carbonaceous material from coals of any rank from and including anthracite to lignite, including such carbonaceous material which is chemically reactive. The term rank is used herein in the sense commonly used in the coal industry, namely, to distinguish coals of different characteristics.

The major source of metallurgical carbon has long been the coke produced by the various high-temperature coke oven processes. Smelters of iron, phosphorus, zinc, lead, tin, silicon and others are users of such coke. These ovens require increasingly expensive and sparsely located coking coals. Marketable supplies of coke breeze and similar by-product sizes of coke formerly available from captive coke ovens are dwindling because the sintering process has enabled producers of such coke to utilize these materials (breeze and other sizes of coke) to advantage in their own operations.

In many areas of the country, more particularly in the vicinity of western mining and smelting regions, there exist vast deposits of low-grade, hydrous, highvolatile bituminous and sub-bituminous coals and lignites. These coals are widespread and some are easily won by strip mining or other low-cost mining techniques. These coals are generally non-agglomerating or weakly agglomerating in nature and cannot be used in the known coking processes to produce a satisfactory source of metallurgical carbon. In many cases, although surrounded by large reserves of such coal, Western smelters pay high freight rates to transport expensive cokes from long distances.

Furthermore, the by-product coke oven presents undesirable operational characteristics in that it requires extensive equipment for blending and sizing coals, entailing difficulties and a high degree of maintenance. By the very nature of the coals required for coke oven processes, varying degrees of agglomeration adversely affect the process. Being a batch operation, the temperature within the coke ovens (whether they are of the by-product, bee-hive or other varieties) varies over the period of reaction time as well as throughout the oven. This results in products whose characteristics difier widely from charge to charge as Well as within a given charge. In all heretofore known coking procedures the period of time required for reaction is measured in terms of many hours. In by-product coke ovens, this period may range from 16 to 48 hours. In bee-hive type ovens, this period may run as long as 72 hours. Generally speaking, metallurgical cokes produced in high temperature ovens have relatively low compressive strength (in the region of 500 to 800 pounds per square inch) and low abrasion resistance (roughly 50% to 70% .as determined by ASTM tumbler index). Thees products also have a low density (caused, no doubt, by rapid and irregular heating rates) and low reactivity (caused by excessive exposure to elevated temperatures).

3,140,241 Patented July 7, 1964 Much development and research has been devoted to low-temperature carbonization techniques, i.e. carbonization at temperatures of from 800 F. to 1200 F. Such procedures yield weak cokes or chars having properties which render them unsuitable, as a general rule, as a metallurgical carbon. To the extent such processes have been used commercially, it has been primarily to produce liquid and gaseous distillates relatively low in aromatics, with the by-product char suitable primarily for fuel. Low-temperature carbonization procedures (at least in the United States) have thus far not met with commercial acceptance.

The processing of finely divided coal particles in fluidized beds has been suggested and much research has been devoted to such techniques. It is well known that many coals, when ground to fine particle size and fluidized in hot gases, produce a characteristically expanded hollow structure known as a cenosphere. This is believed to occur when the devolatilization (which evolves gases in volumes many times greater than that of the solids) is carried out at temperature ranges or other conditions under which the coal particles have relatively high plasticity, i.e., low viscosity, and resulting low pore-wall strength. Even avoiding formation of cenospheres, fluidized carbonization, as heretofore conducted, tends to produce porous, weak and friable chars of low density, completely unsatisfactory for metallurgical uses even when briquetted. Chars produced by both low and high temperature fluid bed techniques as heretofore practiced have puffy and highly figured external surfaces, with little or none of the original coal particle structure preserved; on the contrary, they have the typical open pore structure of common chars.

The briquetting of chars produced by low or high temperature carbonization processes (including fluidization techniques) as heretofore carried out, results in products which are inherently non-homogeneous. This lack of homogeneity manifests itself in that Within the struc ture of the final briquette can be discerned, by normal optical microscopy, the original, individual char particles cemented in place by coke produced from the binder. In eifect, cokes of two genera exist side by side, possessing inherently diiferent characteristics which render the final briquettes unsuitable for metallurgical uses. Experience has indicated that binder-coke will react at different and faster rates than char-coke with the consequent disintegration of the briquette structure to the original fine particles of char-coke. These particles are then subject to discharge from the process without having been utilized in the reaction involved, causing serious economic penalty and technological difliculties.

It is among the objects of this invention to provide a process for treating coals of any rank (in particular the cheap widely available coals of non-coking quality) to produce a product possessing, essentially, the same structure and apparent density as the parent coal, but in which the volatile matter of the parent coal has been reduced to 2% or less.

It is a further object of this invention to provide a process for treating coals of any rank (in particular the cheap, widely available coals of non-coking quality) to produce physically strong, chemically reactive carbonaceous material suitable for use, among other uses, as a metallurgical carbon.

It is another object of this invention to provide a process for treating coals of any rank (in particular the cheap, widely available coals of non-coking quality) to produce a product of controled chemical reactivity. This controlled chemical reactivity is manifest by unexpectedly high reaction rates of this product with gases such as oxygen, steam, carbon dioxide, chlorine, etc.

It is a further object of this invention to provide a process for treating coals of any rank (in particular the cheap, widely available coals of non-coking quality) to produce a product of desired predictable physical characteristics (density, structure, hardness, strength, and similar properties).

It is a further object of this invention to provide a process of producing a product, herein called calcinate, which has the property or properties which enable this material to be combined with a binder, the mixture compressed (e.g., briquetted, extruded, or the like) and further processed to produce a dense unit of any desired shape or size possessing qualities rendering it eminently satisfactory for such end uses as smelting of ore and carrying out chemical reactions.

It is still a further object of this invention to provide a process which produces from certain ranks of coals such as the bituminous, sub-bituminous and lignitic coals, all or a part of the binder necessary for formulation of the aforesaid dense units (briquettes, extrusions, etc.).

It is still a further object of this invention to provide a process of producing compressed shapes from bituminous, sub-bituminous and lignitic coals, in which process a balance is maintained between the production of char and tar so that the amount of tar is not in excess of and preferably adequately supplies the binder requirements for making compressed shapes from the char.

It is yet a further object of this invention to provide a process requiring for its practice less expensive equipment which equipment is more easily maintained, is more thermally efficient and easier to start up, operate, and shut down than conventional by-product ovens for coking coals.

Other objects and advantages of this invention will be apparent from the following detailed description thereof.

In the accompanying drawings,

FIG. 1 shows, for purpose of exemplification and to facilitate a better understanding of this invention, a box diagram of the sequence of steps of the process resulting in the compressed coke shapes, and

FIG. 2 is a flow sheet showing a preferred arrangement of equipment for carrying out such process.

Referring first to FIG. 1, in accordance with the present invention, chemically reactive carbonaceous material is produced from coal of all ranks from lignite through anthracite by a procedure involving the following stages:

(1) The coal, if not already finely divided, is ground, for example, in a hammer mill, to a particle size small enough to be readily fluidized.

(2) These ground coal particles are pretreated (catalyzed) in an environment of such characteristics that as the parent coal passes into and through the succeeding carbonizing stage a reduction in the hydrocarbonaceous volatile content and a polymerization of the remaining hydrocarbonaceous matter of the coal takes place and this without destroying the original physical structure of the coal. This effect is presumed to involve the formation of catalysts of peroxide or hydroperoxide nature which are formed from a portion of the contained oxygen in the parent coal and/or from oxygen derived from the steam and/or air atmosphere in which this step is carried out.

This step must be carried out within a certain temperature range which varies from coal to coal, which is dependent, in part at least, on the time the parent coal is subjected to such temperatures, and which is limited by the distinguishable phenomena hereinafter set forth. The upper temperature limit, regardless of time, is that temperature above which the distilling vapors form tar when condensed. The lower temperature limit is that temperature at which contained moisture is evolved from the parent coals.

The residence times between these temperature limits necessary to accomplish this catalyzing effect depends on the processing treatment employed, the temperature within the limits stated and the rank of coal being processed.

Two further but important secondary effects of this stage, incidental to the primary purpose of catalyst formation, are:

a. The moisture content of the parent coal is reduced to limits found necessary for proper operation of the carbonizing stage, usually to 2% or less;

b. Where such exist, the coking and caking tendencies of the parent coals are destroyed by a small addition and/ or recombination of oxygen, derived from the parent coal or the atmosphere in which this stage is conducted, to form carboxylic groups as are found in humic acids.

These catalyzed coal particles are pyrophoric and should be handled in transport by procedures that will prevent undesirable oxidation.

This stage, which results primarily in effective catalyzing of the coal, is hereinafter and in FIG. 1, referred to as the catalyzing Stage. The products are referred to as Catalyzed Coal.

(3) The aforementioned catalyzed coal particles are subjected to further heating at rates and residence times, hereinafter set forth, to produce the desired density and reactivity characteristics in the calcinate product, i.e., that resulting from the subsequent stage.

The purpose of this 3rd stage is to carry on that type of polymerization which is promoted and directed by the catalysts (presumed to be formed in the catalyzing stage) in such a manner that a substantial portion of the parent coal constituents are retained in a form of the parent coal structure while, at the same time, an amount of these constituents (predicated on the predetermined environment of this stage) is evolved as vapors which may be condensed to form tars and gases for use in subsequent demands of the process. This stage effects a reduction in what is conventionally called the volatile combustible matter (VCM) in the parent coal.

The necessary heating rates and residence times may be achieved by introducing the catalyzed coal into a fluid bed reactor where the temperature rise is effected practically instantaneously, and where the residence time of the catalyzed coal in this environment is controlled by the desired physical and chemical properties of the product. Within the limits hereinafter set forth, longer residence times, for a given temperature, produce higher densities but lower reactivities. Higher temperatures for a given, but shorter, residence time produces higher reactivities but lower densities. The properties imparted to the product char from this stage bear on and reflect directly in the products from the succeeding stages.

The heat for this stage is best obtained from combustion of such a portion of the catalyzed coal particles as is needed to supply the heat demands of the reaction, and control of this combustion is effected by admitting only that amount of oxygen (preferably as air) as will maintain this prescribed level of combustion.

These char particles are pyrophoric and should be handled in transport by procedures that will prevent undesirable oxidation.

Hereinafter and in FIG. 1, this stage is referred to as the carbonizing Stage and the solid product from this stage is referred to as Char.

(3a) The condensed, recovered tar vapors from the carbonizing stage are treated to produce a binder suitable for subsequent blending with the calcined char. This treatment consists of air or steam blowing. These tars, which have been drained of free water, are held at temperatures above the condensation point of steam but below that level where the passage of gases (air or steam) through the tar mass will cause distillation of light ends in excess of by weight of the dry tar being so treated. This treatment is continued until a suitable viscosity increase is obtained, as hereinafter disclosed.

When binders derived from other sources are used,

this treatment may or may not be employed.

(4) The char is subjected, preferably immediately, to further heating to reduce the remaining volatile content in the char to a 3% maximum. This, when effected in a fluidized bed with combustion of a portion of the char to provide the desired temperature, must be done in an atmosphere containing no more of such active gases as will produce the heat and no more carbon dioxide than will be produced by the combustion of that part of the char particles necessary to supply the heat demanded by this reaction.

These calcined particles are pyrophoric and should be handled in transport by procedures that will prevent undesirable oxidation.

Hereinafter and in FIG. 1, this stage is referred to as the Calcining Stage and the product from this stage is referred to as Hot Calcinate.

(5) The hot calcinate is immediately and rapidly cooled to a temperature at which subsequent blending with the binder is effected, or to below 400 F., or to the temperature at which the calcinate is to be used when the calcinate is to be utilized as such. If used at a lower temperature, such cooling may be effected by introducing the hot calcinate into a fluid bed maintained at the temperature to which the calcinate is to be cooled, or accomplishing this stepwise by use of two or more fluid beds if heat economy so dictates. The effect of such cooling is to reduce loss of product by oxidation upon contact with air and, at the same time, to maintain the structure of carbon surface by preventing this oxidation.

Hereinafter and in FIG. 1, this stage is referred to as the Cooling Stage, and the product from this stage is referred to as the Calcinate.

The chemically reactive carbonaceous material or calcinate thus produced may be utilized as such, for example, as raw material for water gas or other gas reactions in the place of coal or coke, or for effecting the reduction of ores as in sintered iron processes. It is remarkably strong, abrasive-resistant, homogeneous, of

high bulk density, and exceptionally uniform in reactions with carbon dioxide, steam and oxygen.

These calcined particles are pyrophoric and should be handled in transport by procedures that will prevent undesirable oxidation.

(6) The calcinate is mixed with a binder (preferably the tar produced in carbonizing the parent coal after this tar has been treated by heat and air-blown to a prescribed softening point hereinafter disclosed) in such a manner that all the calcinate particles are surfacecoated with the binder, a minimum of absorption occurs, and the calcinate and binder are so intermingled that subsequent processing causes co-polymerization of the binder and calcinate. This reaction is exothermic; the temperature of blending or mixing should be maintained at not more than 30 to 60 F. above the ASTM softening point of the binder used.

This stage, which effects the blending of binder and calcinate, is hereinafter and in FIG. I referred to as the Blending Stage and the product is referred to as the Blended Material.

(7) The blended material is subjected to a compacting operation to form any shape demanded (as by briquetting, extrusion or any similar process) wherein the applied pressure on the blended mass is of such magnitude that the shape, when freed from the mold or die, will retain its form and be capable of withstanding abuse and handling at normal and elevated temperatures.

This product is pyrophoric and unstable and consequently should not be stored.

Hereinafter and in FIG. 1, this stage is referred to as the Green Shapes (briquettes, extrusions, etc.).

(8) The green shapes from the forming stage are subjected to further processing by heating in an oxygencontaining atmosphere until co-polymerization of the binder and calcinate have been completed. In this stage the residence time and temperature are interrelated. This curing can be accomplished at room temperature in a matter of days, or at elevated temperatures, hereinafter given, in a matter of 60 to minutes. Longer times at elevated temperatures affect the strength adversely. Accelerators can be used to reduce the time.

The minimum quantity of oxygen required in the curing atmosphere is 2.5% by volume; more can be used, if desired, up to a maximum of 21% under the conditions hereinafter set forth.

The purpose of this curing stage is to promote maximum polymerization, presumably by peroxide or hydroperoxide catalyzation, between the binder and calcinate and thereby prevent formation of coke from the binder alone. This co-polymerization apparently acts to decrease the vapor pressure of the binder-calcinate system to such a level that, in the subsequent stage, coke is' formed from the co-polymers preferentially to distillation of the high vapor pressure components of the original binder.

This product is pyrophoric.

Hereinafter and in FIG. 1, this stage is referred to as the Curing Stage and the product from this stage is referred to as Cured Shapes (briquettes, extrusions, etc.). 7

(9) These cured shapes are heated to reduce the volatile content, increase the strength, adjust the reactivity and produce the massive carbonaceous material final product. This is best accomplished by coking in an atmosphere substantially free of such reactive gases as carbon dioxide (which will react with the carbon of the massive forms to produce carbon monoxide and reduce yield and strength), oxygen (which will react with the massive shapes to produce carbon monoxide and reduce the yield and strength), and steam (which will react with the carbon of the massive shapes to produce hydrogen and carbon monoxide and reduce the yield and strength).

A secondary detrimental effect of such side reactions is the partial consumption of individual shapes causing undesirable non-uniformity of size and surface.

This treatment must take place at a temperature sufficient to reduce the volatile combustible content of the final product to 3.0% or less.

The time necessary to accomplish these aforementioned ends is dependent on the temperature andis the time necessary for the coking reaction to reach that stage of completion at which the coke shapes have the desired strength.

- The heat for this reaction is preferably supplied by direct contact with hot inert gases (for example, carbon monoxide or hydrocarbon gases produced in earlier stages) as in a shaft or on a moving grate. However, any other means of raising these cured shapes to the temperatures dictated by the specifications for the final product may be used. Such means may be direct or indirect, as by gas contact or by radiation from externally heated walls, or by direct radiation sources.

The shapes, after having been subjected to the hightemperature treatment, must be cooled, preferably but not necessarily in the same apparatus, but in any case in an atmosphere free from reactive gases, as previously described, to such a temperature that harmful and yieldconsuming reactions with reactive gases do not take place.

Hereinafter and in FIG. 1, this stage is referred to as the Coking Stage and the product from this stage is referred to as Coke Shapes (briquettes, extrusions, etc.).

These shapes are exceptionally uniform in that the product, from boundary to boundary, is a homogeneous entity, as indicated visually by optical microscopy and chemically by the uniform, homogeneous consumption of the shape from all dimension in any reactive medium. These shapes have a high strength (denoted by resistance to compressive pressures on a 1%" diameter x high cylindrical form) of at least 3000 pounds, a high bulk density, exceptional resistance to abrasion, and unusually high surface area for such high strength.

The chemical reactivity, as above noted, depends on the process conditions. Thus, coke shapes of desired chemical reactivity, many times that of high-temperature coke, can be produced. Coke shapes as reactive or more chemically reactive than highly active coconut charcoal have been produced. By coking at elevated temperatures, hereinafter disclosed, coke shapes of high strength and low chemical reactivity result.

The characteristics listed are not all-encompassing. These final coke shapes posses other desirable qualities which will become apparent from the further description of the process.

In describing the process steps and the reasons therefor, we have tried to make understandable the influence: and importance of each step to the subsequent steps; however, the invention is not to be limited by any )theoretical interpretations expressed herein.

In view of the known differences between coals of different ranks, and even between different beds of coal of the same rank, it is indeed surprising and unexpected that the procedure embodying this invention can be applied to coals of all ranks to produce calcinates and/ or massive shapes of equivalent quality.

The preferred conditions generally applicable to lignites, high-volatile non-coking coals, coking coals and anthracitesof each of the above stages will not be described.

THE GRINDING STAGE In the practice of this invention, the coal, if not already of the required finely divided size, may be ground by any standard grinding and sizing technique to produce a natural distribution particle size, substantially all of which passes a No. 8 mesh screen and at least 95% of which is retained on a No. 325 mesh screen and with a minimum quantity of fines of a size which would escape from the cyclone of the fluidizing bed reactors. This is reading accomplished by grinding in a hammer mill.

THE CATALYZING STAGE These finely ground parent coal particles are first subjected to pretreatment, desirably in a fluidized bed, but alternatively in a dispersed phase, to promote, presumably, the formation of peroxide and hydroperoxide catalysts. This is best accomplished in an atmosphere containing oxygen, the concentration of which will vary inversely with the oxygen concentration of the coal being so catalyzed. The practical range is 1% to 20% by volume in the entering fluidizing medium, depending on the rank of the coal. For low-rank, non-coking coals, a volume of oxygen at or near the lower limit of this range is employed, e.g., from 1% to 8% by volume; for coking coals, a volume of oxygen in the upper part of this range is used, e.g., from 8% to 20% by volume. In general, the concentration of oxygen used will be that optimum quantity of oxygen which will add to the coal matrix and thus provide a source of oxygen for catalyst formation and inhibition of agglomerating tendencies if present, without causing an uncontrolled combustion in this catalyzing stage or in the later stages of the process.

In this catalyzation of non-coking coals, including lignites, the fluid bed is normally maintained at a temperature of 250 F. to 500 F.; for coal possessing caking and coking characteristics, in order to promote the secondary effect of destroying these characteristics, the bed is maintained at a temperature of 500 F. to 800 F. The maximum of the range is that point in temperature at which hydrocarbon vapors, the tar precursors, i.e., tarforming vapors, begin to be evolved. The lower limit is that temperature necessary to reduce the moisture con- 8 tent to 2% or less, or, in the case of coal with less than 2% moisture, that temperature at which oxygen can be added to the coal matrix.

In carrying out this catalyzation, the parent coal may be introduced into a cold fluid bed and subjected to a gradual rise in temperature to the range indicated. Preferably, the parent coal is introduced continuously into a fluid bed maintained at the desired temperature at which destructive deformation of the coal particles does not take place and wherein the heating rate will be of shock or instantaneous magnitude, for 1 second or less.

When heating the coal particles under fluidizing conditions, the coal particles should remain in the fluid bed for an average residence time of at least 5 minutes, and preferably from 5 minutes to 3 hours. This catalyzing may be accomplished in times as low as 10 minutes, or as high as minutes, Without the occurrence of deleterious effects on the final product. The temperature of catalyzation, within the ranges given, bears an inverse relationship to the residence time. In catalyzation of non-coking coals at temperatures in the lower portion of the range of 250 F. to 500 F., the times should be in the upper portion of the residence range. On the otherhand, when operating at the higher temperatures, near 500 F., the residence time should be in the lower portion of this time range. Similarly, when processing coking coals, longer residence times within the range of from 5 minutes to 3 hours are employed when operating near 500 F. and the shorter residence times when operating near 800 F. The times and temperatures of catalyzation for anthracite coals are substantially the same as for coking coals.

The fluidizing medium, desirably steam or flue gas diluted with air or oxygen, is introduced at a pressure of from 2 to 30 p.s.i.g. The fluidizing medium is introduced at a velocity to give the desired boiling bed conditions, e.g., from about 0.5 to 2 feet per second superficial velocity.

Heating of the finely divided coal particles in the fluidized bed may be effected by burning a small portion of the coal, by sensible heat introduced in the fluidizing medium, or by indirect heat exchange.

In lieu of effecting catalyzation of the coal in a fluidized bed, the finely divided coal particles may be subjected to heating in a dispersed phase, i.e. dispersed in a suitable gaseous medium (e.g., flue gas, nitrogen, or carbon dioxide containing oxygen, within the limits heretofore prescribed) of suflicient velocity to maintain the particles in the dispersed phase rather than in the dense phase, as in a fluidized bed. Utilizing dispersed-phase heating, non-coking coals are heated to a temperature of 350- 750 F. for about 3 seconds. Coking coals are heated to a temperature of 7501000 F. for about 3 seconds.

Catalyzation, as hereinabove described:

(1) Conditions the parent coal so that in further processing in the succeeding stages, a controlled amount of polymerization occurs which effectively increases the strength and thickness of the pore walls while permitting a predetermined amount of the coal constituents to evolve as gas and vapors, which vapors are subsequently condensed to tar to fill the demands of the total process;

(2) Effects the removal of contained moisture when hydrous coals are treated;

(3) In the case of coals which have a tendency to agglomerate, the treatment inhibits this tendency.

These effects are accomplished without sacrifice of the continuity-of-structure characteristics of the parent coal.

THE CARBONIZING STAGE Carbonization is carried out by subjecting the catalyzed coal particles to a further heat-treatment in a fluidized bed where the heat requirements are supplied, preferably, by the oxidation of a limited amount of the catalyzed coal or of the hydrocarbon vapors derived therefrom. This oxidation is controlled by the admission of only that 9 amount of oxygen necessary to produce the desired temperature level. This oxygen is admitted to the bed in the form of air as a component of the fluidizing medium, the remainder of which may be steam, nitrogen, flue gas, carbon dioxide, carbon monoxide, or any gas which is not reactive with the catalyzed coal in this stage. Alternatively, heat may be supplied externally by use of heat exchangers.

In this stage the catalyzed coal particles may be heated under conditions:

a. So controlled as to produce a char having the desired optimum properties;

b. So controlled as to produce only that amount of tar consistent with the quantity of binder required for blend specifications;

0. So controlled as to produce the maximum of tar, which, in case of anthracite or other low volatile coals, may be insufficient to satisfy the binder requirements under paragraph b. 1

Optimum conditions of the carbonizing stage will vary from coal to coal and may be determined for each rank of coal processed by prior laboratory evaluation in benchscale apparatus.

Temperature and residence time are critical. The lower limit of temperature is that temperature at which the activated coal begins to evolve tar forming vapors in quantity and this temperature is the same as the upper limit of the catalyzing stage for any given coal, i.e. 800 F. for coking coals, and 500 F. for non-coking coals.

The upper limit of temperature is that temperature above which the expanding coal particles form cracks, fissures and bubbles to such an extent that retraction to the size and shape of the original coal particle cannot occur. This upper temperature limit is approximately ll50-1200 F. In general, the higher the temperature of carbonization (within the lower and upper limits), the greater the quantity of tar produced.

The oxygen-containing fluidizing gas should enter the bed at a temperature not much below the temperature of the fluidized bed and not more than 20 F. above this temperature; if this fiuidizing medium is introduced at a much lower'temperature than the bed, more of the catalyzed coal and hydrocarbon vapors will have to be burned in order to supply the heat necessary to raise the fluidizing medium to bed temperature, thereby reducing product yields. If oxygen-containing fluidizing gases enter the bed at a temperature of more than 20 F. above the temperature of the bed, weak non-uniform char results.

The fluidizing medium is introduced at such superficial velocities as will effect the desired fluidization pattern, usually 0.5 to 2 feet per second and, desirably, at pressures consistent with the smooth operation of the Whole process, e.g., 2 to 30 p.s.i.g., preferably about 5 p.s.i.g.

The material in the bed is maintained at the aforementioned bed temperature for to 60 minutes. The residence time at this point is a source of control of the chemical reactivity and other characteristics of the finalcalcinate or massive shape and is determined by the specification set for the final calcinate or massive shape derived from the calcinate. In the case of coals below the rank of anthracite, sufficient binder is produced to supply the needs of massive formation. With anthracites such is not the case; the carbonization step partially de-gases and conditions the anthracite structure for further treatment in succeeding stages of the process.

The carbonization may be carried out as a continuation of a batch-operated catalyzing step wherein, particles being catalyzed having been held at the desired temperature for the specified residence time, the temperature of the bed is raised as rapidly as the reaction of the oxygen content of the fluidizing medium with the bed will achieve carbonization temperatures. Or, preferably, this carbonization may be carried out by continuously feeding the catalyzed coal from the catalyzing stage directly into a '10 fluid bed maintained at the carbonizing temperatures as previously described. In this case the heat transfer rates within the bed are of such a magnitude as to effect instantaneous shock heating of the particles.

Unless the parent coal particles have been treated as prescribed in the catalyzing and carbonizing stages, irreversible expansion of the particles results from nonelastic rupture and explosion of the pore walls. The resulting chars, while useful as boiler fuels, cannot be further processed to produce the calcinate or massive shapes that will be competitive with or superior to the cokes from by-product, bee-hive or similar ovens.

It is only by following the sequence of stages above described that high-density, high-strength calcinate particles (which may be subsequently formed into homogeneous stable shapes) result.

RECOVERY AND PREPARATION OF THE TARS That controlled portion of the coal constituents which is evolved as gas and vapor from the coal particles may be processed to produce tars and gas for use in the process. The vapors may be cooled by direct contact with a recycling water spray to such a temperature that about of the vapors are condensed to tar. The uncondensed 20% goes forward through conventional heat exchangers and is cooled to about 40 F. above the cooling medium temperature which circulates indirectly over the heat exchange surfaces at which temperature some further condensation takes place. The two condensates are combined to give the total wet tar which is allowed to settle, and the water is decanted to leave a decanted tar of about 4%6% moisture content.

Alternatively, the gas and vapor stream may be cooled by direct spray, or, conventionally, through indirect heat exchangers to such temperatures as will totally condense the tar precursors to tar and allow only the normally non-condensable gases, such as methane, etc., to leave the heat exchangers. This results in a total condensate, not separate fractions. This total condensate is then decanted in the manner heretofore described.

Blowing the decanted tars so formed simultaneously dehydrates the tar to a water content of 0.5% and increases the tar viscosity to the desired softening point. A softening point within the range of to 225 F. preferably to F. (ASTM Ring and Ball) is satisfactory for use as the binder.

This blowing is accomplished by the injection of air through a suitable sparger into the decanted tar. This tar is maintained at a temperature above the condensation temperature of the steam, but below that point at which distillation of the tar light ends exceeds approximately 5%. The retained light ends are converted to binder of proper viscosity during the blowing treatment.

This viscosity increase may be accomplished by incorporating catalysts into the tar after dehydration. Suitable catalysts are organic peroxides, such as benzoyl peroxide, inorganic catalysts such as sulfuric acid, boron trifluoride or its complexes, aluminum chloride, etc. The usable catalyst concentration may vary from 0.1% to 2% depending on the tar, the catalysts and the viscosity range desired.

THE CALCINING STAGE The char particles from the carbonization stage are further heated to reduce the amount of volatile combus- 11 residence time in excess of minutes. A secondary eifect of this calcining is to increasethe physical strength of the calcinate. w

The residence times of the char in this stage are dictated by the specification of the final product and are more or less dependent on the operating temperature. At minimum temperature, sufficient residence time to reduce the volatile combustible matter to 3% is required. Practically, this limit is 10 minutes at about 1400 to 1500 F. and should. not be less than 7 minutes even at 1800" F.

The fiuidizing atmosphere necessary in this stage should be free of reactive gases such as carbon dioxide or steam. Oxygen can be tolerated only in such an amount as is demanded by that oxidation rateof the char necessary to supply the heat demands of this stage. This oxygen is most practically obtained from air introduced as part of the otherwise chemically inert fiuidizing medium, and the concentration of air for this purpose in these entering gases shall not exceed 70%.

The remaining components of the fiuidizing medium may be carbon monoxide, hydrogen, nitrogen and flue gas in which carbon dioxide and water have been reduced to carbon monoxide and hydrogen by. previously passing the flue gas over a bed of hot carbon, or otherwise.

This fluidizing medium should be introduced at such pressures as are consistent with smooth operation of the fluidization process; a range from 0 to 30 p.s.i.g., preferably about 2 p.s.i.g., is satisfactory. The velocity of this medium should be consistent with a proper fiuidizing pattern, or the same as in the carbonization stage, e.g., 0.5 to 2 ft. per second.

It is advantageous to introduce the fiuidizing medium at about the operating temperature of the bed. Lower than bed temperatures will demand increased oxidation of the char, with resulting deleterious effect of water vapor and carbon dioxide on the final product.

The heating may be accomplished as a continuation of the catalyzing and carbonizing stages, in the same batch-operated fluidized bed reactor, by raising the temperature of the bed to the desired calcining range, and holdingthe bed at that range until calcination has been completed. Or, preferably, the hot char may be introduced continuously and directly to a fluidized bed operating at the specified calcining temperature. In this case, the rate of heat transfer in the fluid bed is of such magnitude as to eifect shock or instantaneous heating of the char to calcining temperature.

Unless the parent coal has been treated as prescribed in the catalyzation and carbonization stages, this shock heating will shatter the particles, producing extremely low apparent density, highly exploded fines. Such particles give evidence that the structure, density and fracture of the parent coal has been completely, adversely and permanently altered.

The calcinate produced by observing the conditions hereinabove described has the essential structure and apparent density of the parent coal particles.

THE COOLING STAGE The calcinate must be cooled rapidly and immediately to prevent loss of reactivity. This cooling, desirably, is effected in one or more fluidized beds, preferably two, in which the fiuidizing medium also serves as the cooling medium and in which the heat transfer rate is of such magnitude as to effect instantaneous cooling. Suitable cooling media are flue gas, nitrogen, or carbon monoxide, introduced at a temperature to effect the desired cooling and at a velocity to effect the desired fluidization. The velocity may be substantially the same as that employed during the carbonization of calcination treatments. Cooling atmospheres containing appreciable amounts of oxygen, water vapor or carbon dioxide should be avoided because, in view of the highly reactive nature of the calcined char, such atmospheres may result in deleterious effects on the calcinate.

Where the calcinate is employed in producing massive shapes, it is cooled 'to a temperature approximately 30 to 60 F., preferably about 50 F. above the softening point (previously described) of the bituminous binder employed in the forming operation and used without appreciable time delay or exposure to air.

'When producing calcinates for use as such, the calcinate must be cooled to approximately room temperature for storage or transport unless immediately used in high-temperature applications. This calcinate is pyrophoric; hence, if stored, it should be stored in a nonexidizing atmosphere so that it will not catch fire.

THE BLENDING STAGE In order to produce massive shapes such as briquettes, extrusions, castings, etc., the highly reactive calcinate must be cooled to the proper temperature, 30 to 60 F. above the ASTM Ring and Ball softening point (100 to 225 F.) of the binder employed.

At this point the calcinate is mixed with the prepared binder, which is introduced at the proper mixing temperature, as heretofore specified, in proportions of from %90% calcinate to 25%l0% binder. The percentages are based on the'weight of the total mix.

These limits are critical, not only from the standpoint of co-polymerization and the production of final massive shapes of desired strength, but also from the standpoint that the green shapes must stand mechanical handling. Below the lower limits of this range ratio of binder to calcinate, the green shapes will tend to fall apart as a dry mix. Above the upper limits of this range, the green shapes will soften, sag and agglomerate during curing, with attendant losses and process difficulties.

The optimum ratio for dry calcinate to binder is determined by laboratory tests to give the strongest prodnot consistent with high yields. If too much binder is used, the unneeded portion will distill out; if too little is used, the shapes will disintegrate in curing and coking, with attendant high losses due to the production of fines.

It is advantageous to complete blending in the time it takes to actually coat the calcinate particles with a uniform layer of binder; the time during which the mixing or blending is effected, is not critical.

Preferred binders are coal tar pitch or pitches produced by the condensation of tars from the gases evolved during the carbonization and subsequent dehydration and oxidation of the resultant tar to produce pitches having a softening point of from to 225 F. (ASTM Ring and Ball as described). High-temperature or low-temperature coal tar pitches are satisfactory.

' When mechanical pressure is used to form the shapes, i.e. extrusion or briquetting, from this mixture of calcinate and binder, pressure in excess of 5,000 pounds per square inch is desirable. Below compacting pressures of this magnitude, the shapes will be sandy and tend to fall apart. Below this compacting pressure, the shapes will, on final processing, not meet the requirements for physical strength. The maximum pressure usable and de sirable depends on the size of the shapes and the type of equipment used. The higher the pressure, generally speaking, the greater the crushing strength of the final coked shapes.

Formingv to shapes can be carried out in any conventional briquetting or pelleting equipment to produce briquettes, or pellets of any desired shape. Thus, the briquetting equipment may be molds or rolls in which the mixture is subjected to pressure. Alternatively, extrusion equipment may be used to extrude the mixture in the form of rods of any prescribed cross-section, and the rods may be cut into desired lengths to produce the shapes required. Surface-tension pelletizing equipment can, of course, be used.

The size and form of the shapes will be dictated by THE CURING STAGE The shapes so formed from this calcinate and binder blend are pyrophoric and unstable and cannot be stored in bulk. They are moved directly to the curing stage wherein the co-polymerization is initiated and sustained by subjecting the green shapes to treatment with, or without, heat in an atmosphere containing from 2.5% to 21% oxygen. The composition of this atmosphere may be achieved by use of 100% air at low temperatures and low bed heights or by dilution of the air with gases (e.g., carbon monoxide, nitrogen, flue gas containing little or no water vapor, or carbon dioxide) which are inert to the shapes and to the volatile hydrocarbonaceous components of that portion of the binder which is substantially unreacted.

- Practically, thisco-polymerization is achieved at the maximum reaction temperature consistent with the amount and nature of the binder and yet below the ignition point of the volatile hydrocarbonaceous components of the binder which may exist in combustible concentrations (outside the massive shape). The temperature must not exceed 50 F. below the coking point of the binder as determined in the ASTM distillation by that point at which the coke begins to appear on the side of the distillation flask. Such coking of the binder must be avoided since that'quantityof binder which forms coke during curing reduces, directly, the amount of co-polymerization of the binder and calcinate'. These co-polymers form the' homogeneous precursors of the chemically uniform, physically strong, coke briquettes.

Curing has been effected at room temperature in 100% air (20% oxygen) by holding the shapes under such conditions for 4 days with the shapes so distributed that the heat generated is readily dissipated.

Curing is practically and preferably accomplished by subjecting the. green shapes to an atmosphere of 2.5 21% by volume of oxygen at maximum temperature (450-500 F.) for, 90 to 180 minutes, preferably about 2 hours. The curing conditions that must be maintained for an acceptable product are a function of oxygen concentration in the curing atmosphere, temperature of the curing environment, thickness or heightof the bed of massive shapes, and the rate at which heat is introduced and removed from the bed. Oxygen is needed in this stage as the catalyst or catalytic raw material. If the green shapes are subjected to temperatures above the softening point of the unreacted binder in concentrations o'fbxyg'e'n below 2.5%, disintegration of the shapes takes place at an extremely rapid rate. On the other hand, at temperatures approaching the coking temperature for a given binder and in beds of massive shapes above 24" in height, combustion of the hydrocarbonaceous volatile components of the binder occurs where the oxygen concentration exceeds 4% by volume of the entering curing atmosphere. Hence, under such conditions, the oxygen concentration should be maintained below 4% by volume. With beds of lesser height, the oxygen concentration may be increased accordingly. With beds of 6" or less in height, 20% oxygen (air) may be used in the curing medium.

It is obvious to one skilled in the art that various combinations of these variable quantities within the limits specified may be successfully employed.

This catalytic effect of oxygen may be enhanced, if so desired, by the addition of other catalysts during the 14 curing process. Such catalysts may be incorporated in the green shapes before curing. Such incorporation may be made in gaseous, solution or solid form during blending, or in gaseous or solution form in the curing atmosphere. Suitable catalysts are boron trifluoride and its complexes, aluminum chloride, hydrogen peroxide,

phosphoric acid, etc. The amount of such catalyst employed may be from 0.1% to 5% based on the weight of the shapes. Maximum or near maximum strengths result, for example, with the boron trifluoride complexes and aluminum chloride in about 60 minutes curing time. In the case of hydrogen peroxide or phosphoric acid, minutes curing time gives maximum strength briquettes.

The velocity of the curing atmosphere passing through the bed of green massive shapes is a function of the THE COKING STAGE The cured shapes are subjected to coking at temperatures and times of such magnitude as to insure the reduction of the volatile combustible content (VCM) to a value below 2%. At the same time, this treatment eifects an increase in strength and helps create that degree of reactivity specified for the end product. This is normally accomplished at temperatures above l500 F. for at least 5 minutes in an atmosphere such as that hereinafter disclosed. At 1500 F., a minimum time of 15 minutes is required; at 1700 F., a minimum time of 10 minutes is required. At 1500 F. coking can be continued for about one hour without loss of reactivity. At 1700 F. coking can be continued for about 40 minutes without loss of reactivity.

The effect of higher temperatures is to increase the strength (resistance to crushing pressures) and decrease the chemical reactivity. These effects are also achieved by increasing the residence time at any given temperature. Temperatures in excess of 1750 F. are employed where a low reactivity product is desired. At temperatures as high as 4000 F. with a residence time of about 90 minutes a product results having high strength but low chemical reactivity suitable for structural uses such as fabrication of piping and vessels for the chemical industry, and for cathode liners in cells employed for the reduction of aluminum bearing ores to the virgin metal.

' Flue gas passed through an incandescent bed of carbon to reduce the carbon dioxide content to below 10% by volume is a desirable medium for supplying coking heat to the shapes. Hydrogen, carbon monoxide, nitrogen, hydrocarbon gases, and the tar-free gases generated in the calciner may be used for this purpose.

This stage results in coke formation from the copolymerized binder and calcinate in the cured shape to produce a chemically and physically uniform carbon structure in the final product.

The coking may be effected in a coking kiln, desirably, a vertical kiln, into the top of which the cured shapes are introduced and gravitate downward countercurrenlt to the hot gases. Alternatively, the coking may be effected on a traveling grate passing through a suitable furnace.

The coked briquettes are cooled to a temperature (about 500 F.) at which exposure to air is not detrimental, or to a lower temperature, if desired. Such cooling may be effected by passing cooling gas over or through a bed of coked shapes. This gas must be substantially free of carbon dioxide, water vapor and oxygen. Desirably, it is effected in the lower portion of the shaft kiln, in the upper portion of which the cured shapes are coked.

The resultant briquettes withstand crushing pressures of at least 3000 pounds per square inch, remain stable under all operating and storage conditions, are exceptionally resistant to abrasion, and possess other desirable properties; by observing the necessary conditions herein disclosed, briquettes of desired chemical reactivity result, including briquettes which react uniformly and are eminently satisfactory for use in metallurgical furnaces, such as blast and phosphorus furnaces.

Referring now to FIG. 2, which shows a preferred arrangement of equipment for practicing the process of this invention, 1 indicates the pulverized coal feed to a screw conveyor 2 which discharges continuously into the catalyzer 3. The catalyzer contains a fluidized bed 4 of the pulverized coal particles. The fluidized bed 4 is activated by a hot gat stream 5 containing steam and air. The hot gas stream 5 may be controlled to maintain the desired atmosphere in the catalyzer 3. The catalyzer is equipped with an internal cyclone separator 6 through which gases evolved in the catalyzer are discharged through line 7. The cyclone separator 6 also removes entrained coal particles from the gas and returns the particles to the fluidized bed 4.

The catalyzer 3 discharges coal continuously through line 8 into the carbonizer 9. The carbonizer contains a fluidized bed 10 of the catalyzed coal particles. A stream of hot air and inert gas 11 is supplied as the fluidizing medium. The carbonizer 9 is equipped with an internal cyclone separator 12 through which gases evolved in the carbonizer are discharged. A gas take-01f line 13 leads from the cyclone separator 12 to the condenser 30 hereinafter described. The cylone separator 12 also removes char particles from the gas and returns the particles to the fluidized bed 10.

The carbonizer 9 discharges char continuously through line 14 into the calciner 15. The calciner contains a fluidized bed 16 of the char particles. A stream of hot air and inert gas 17 is supplied as the fluidizing medium. The calciner is equipped with an internal cyclone separator 18 through which fuel gas evolved in the calciner 15 is discharged through line 19. The cyclone separator 18 also removes char particles from the fuel gas and returns the particles to the fluidized bed 16.

The calciner 15 discharges calcined char continuously through line 20 into the cooler 21. The cooler contains a fluidized bed 22 of calcined char particles fluidized by a stream of inert gas supplied through line 23. The cooler is equipped with an internal cyclone separator 24 through which gases are discharged through line 25. The cyclone separator also removes char particles from the gas and returns the particles to the fluidized bed 22. The cooler 21 is also equipped with internal cooling coils 26 through which a suitable cooling medium may be circulated. Calcinate is continuously discharged from the cooler 21 through a rotary valve 27, then through a line 28 to the blender 29.

The tar recovery system comprises a condenser 30 supplied with a circulating cooling liquid to condense the tar and a portion of the Water vapor in the gas which enters the condenser 30 from line 13. Fuel gas leaves the condenser through line 31. Tarry condensate leaves the condenser 30 through line 32 and is discharged into the decanter 33. Tar from the decanter is pumped through line 34 to the conditioner 35. The conditioner is equipped with an agitator 36. The tar in the conditioner can be heated while being agitated and is air blown by air introduced at 37 to remove moisture and raise the tar softening point. Excess gas is removed through line 38. Tar binder is pumped from the bottom of the conditioner through line 39 to the blender 29.

The blender 29 discharges the calcinate-tar mixture through line 40 into the briquette former 41 which produces briquettes. The briquettes are discharged onto conveyor 42 which communicates with the curing oven 43. A stream of hot gas is recycled through the curing oven 15 by blower 44; this gas is heated in the gas heater 45. The desired oxygen. content of the recycle gas is made up by supplying air through line 46. Waste gases evolved in the curing oven are discharged through line 47.

The cured briquettes are discharged continuously from the curing oven 43 into the coker 48. The cured briquettes move slowly through the coker 48 through a flowing stream of inert reducing gas which is continuously removed from the coker by blower 49; the gas thus removed passes through the gas cooler 50. The cooled gas reenters the coker through line 51 near the discharge end to cool the coked briquettes. A portion of the cooled gas passes through a heater 52 and enters the coker through line 53. This gas maintains a high enough temperature to coke the cured briquettes entering the coker 48. Fuel gas evolved in the coker is discharged through line 54. The coked briquettes are discharged into a conveyor 55 and removed to storage.

The following examples are illustrative of the process of this invention. It will be appreciated that this invention is not limited to these examples.

In all examples, coal was ground in a hammermill having a inch mesh screen to produce finely divided coal particles, 100% of which passed a No. 14 Tyler screen size, and of which was retained on a No. 325 Tyler screen size.

The processing of this finely divided coal was carried out in eqiupment, in general, of the type shown in FIG. 2 of the drawings.

Examples I and II involved sub-bituminous coals identified in Table 1 which follows.

In the tables D.B. means dry basis.

Table 1 Example I Example II Specific Species Elkol-Adavllle Seam DI} Clarke N0. 7 &

7 2. Location Kemmerer, Wyoming. Superior, Wyoming.

ank Sub-Bituminous B Sub-Bituminous A. Agglonierating Non-Agglomerating Non-Agglornerating.

Properties.

GENERAL ANALYSIS Heating Value (Ash 10,700 12,300.

Free, Gross B.t.u.). Moisture, wt. percent. 18 11.5. Volatile Matter, wt. 42.7 43.5.

percent, D.B. Fixed Carbon, wt. 53.2 57.5

percent, D.B. Ash, \vt. percent, 4.1 3.5.

D.B. Elemental Analysis, wt. percent, D.B.:

Carbon 70.8 74.9. Hydrogen Oxygen Nltroge The condition of each of the stages or steps are given in Table 2 which follows:

Table 2-C0nt1nued Example I Example II Carhonizing:

Length of Run, Hours 4.1 4. 6 Total Solids Fed, lbs 31 29. 8 Oarbonizer Inside Diameter, Inches... 3.07 3. 07 Temperature of Fluid Bed, F 890 800 Residence Time, Minutes 34.0 21 Fluidlzing Medium:

Superficial Velocity, itJsec 0. 84 0. 8 Composition, Volume Percent:

Oxygen 3.0 3. 3 Nitrogen 49. 43. 1 I Steam 48.0 53. 6 Calcmrng:

Length of Run, Hours 4. 6 Total Solids Fed, lbs 23. 5 23. 4 Calciner Inside Diameter, Inches.. 3.07 3.07 Temperature of Fluid Bed, F 1, 550 1, 655 Residence Time, Minutes 33. 0 22 Fluidizing Medium:

Superficial Velocity, it./sec 1. 09 1. 2 Composition, Volume Percent:

Oxygen 8.0 8 Nitrogen 92. 0 92 Cooling:

Temperature of Fluid Bed, F 400 150 Composition of Fluidizing Medium,

Vol. Percent Nitrogen 1 Nitrogen Temperature of Fluidizing Medium,

F 80 80 Blending:

Kind of Binder Blown Tar from Carbonization 140 F. Softening Point Amount of Binder, Wt. Percent of Total Mix 18 27. 4 Amount of Calcinate, Wt. Percent of Total Mix 82 72.6 Temperature of Blend F 160 160 Time of Blend, Minutes 4 10 Forming:

Type Extrusion Extrusion Pressure, lbs./In. 20, 000 20, 000 Size of Shapes, Inches Outside Diameter x Inches High 1.125 x 0.75 1.125 x 0.75 Curing:

Bed Heights, Inches Temperature of the Curing Atmosphere, F 450=l=10 450:1:10 Composition of the Curing Atmosphere, Vol. Percent:

Oxygen 21 21 Inerts 79 79 Residence Time of Shapes, Minutes... 120 120 Coking:

Bed Heights, Inches. Temperature of the Coking Atmosphere, F 1, 700 1, 700 Residence Time, Minutes 10 10 Composition of the Coking Atmosphere, Vol. Percent:

Hydrocarbons 5 5 Nitrogen 95 95 Coke Yield, wt percent of Coal, D. 58 60 EXAMPLE III This example involved the same sub-bituminous coal as in Example I using larger equipment of the same general type as shown in FIG. 2, The conditions of Example III are given in Table 3 which follows:

Table 3 Catalyzing:

Length of run, hours 87. Total solids fed, lbs 8,5'52 Catalyzcr, inside diameter, inches. 10.02. Temperature of fluid bed, F 372. Residence time, minutes 215. Fluidizing mcdium Superficial velocity, ft./scc 0.86. Composition, volume percent Oxygen 2.0. Nitrogen 7.0. Steam 91.0.

. 18 Carbonizing:

Length of run, hours 87. TotaI solids fed, lbs 7,340. Carbonizer, inside diameter, inches 10.02. Temperature of fluid bed, F 870. Residence time, minutes 53. Fluidizing medium Superficial velocity, ft./ sec 0.88. Composition, vol. percent Oxygen 5.0 Nitrogen 19.0 Steam 76.0.

Calcining:

Length of run, hours 87. Total solids fed, lbs 4,620. Calciner, inside diameter, inches 1,490. Temperature of fluid bed, F 12. Residence time, minutes 21. Fluidizing medium- Superficial velocity, ft./sec 0.54. Composition, vol. percent Oxygen 11.0. Nitrogen 89.0.

Cooling:

Temperature of fluid bed, F 400. Composition of fluidizing medium, vol. percent Nitrogen Temperature of fluidizing medium, F 80.

Blending:

Kind of binder Blown tar from carbonization, F. softening point. 7 Amount of binder, wt. percent of total mix 18. Amount of calcinatc, wt. percent of total mix 82.

Temperature of blend, F 160. Time of blend, minutes 4.

Forming:

Type Pillow V briquettes. Pressure, lbs/in. 20,000. Size of shapes, inches outside diameter x inches high %X% X /2 Curing:

Bed height, inches 84. Temperature of the curing atmosphere, F 450i20. Composition of the curing atmosphere, volume percent Oxygen 3.5. Inerts 96.5. Residence time of shapes, minutes 120.

Coking:

Bed height, inches 72. Temperature of the coking atmosphere, F 1,687. Residence time, minutes 10. Compositon of the coking atmosphere, volume percent Steam 18.2.

Carbon Dioxide 4.1. Hydrocarbons 9.5. Nitrogen 68.2.

75 Coke yield, wt. percent of coal, DB... 58.

Examples IV and V involved bituminous coals, identified in Table 4 which follows and were carried out in the same general type of equipment used in Example I:

GENERAL ANALYSIS Heating Value (Ash Free,

Gross B.t.u.).

Moisture, wt. percent"--.

Volatile Matter, wt. percent, D.B.

Fixed Carbon, wt. percent, .13.

Ash, wt. percent, D.B....

Elemental Analysis, wt.

percent, D.B.:

The conditions of each of the stages or steps of Examples IV and V are given in Table which follows:

Table 5 Example IV Example V Catalyzing:

Length of Run, Hours 13.4 Total Solids Fed, lbs 58 37. 5 Catalyser Inside Diameter, Inche 3.07 3.07 Temperature of Fluid Bed, F 350 600 Residence Time, Minutes 26 44 Fluidizing Medium:

Superficial Velocity, it./see 0. 5 0.8

Composition, Volume percent: Oxygen 1.1 1.4 Nitrogen 40. 4 38 Steam 58. 5 60. 6 Carbonizing:

Length of Run, Hours .11. 5 9. 3 Total Solids Fed, lbs 27 19.4 Carbonizer Inside Diameter, Inch 3.07 3.07 Temperature of Fluid Bed, F..- 820 8510 Residence Time, Minutes 46 32 Fluidizing Medium:

Superficial Velocity, it./seo. 0.7 1 Composition, Volume percent Oxygen. 3. 2 4. 2 Nitrogen 49. 5 45. 2 team...- 47. 3 50. 6 Caleinmg:

Length oi Run Hours 5.5 6.6 Total Solids Fed, lbs- 19 13. 2 Caloiner Inside Diem 3.07 3.07 Temperature oi Fluid Bed, F 1610 1650 Residence Time, Minutes--. 16 37 Fluidizing Medium:

Superficial Velocity, it./Sec.. 1 0.9 Composition, Volume percent Oxygen.. 11. 2 9. 7 Nitrogen 88.8 90.3 Cooling:

Temperature of Fluid Bed, F. 150 150 Composition oi Fluidizing Me vol. pcrcent.. 1 Nitrogen 1 Nitrogen Tern erature o 80 80 Blending:

Kind oi Binder Blown Tar from Carbonization 140 F. Soitening Point Amount oi Binder, \vt. percent of Total M 20 18 Amount oi Cal Total MlX 80 82 Temperature of Blend, 160 160 Time of Blend, Minutes. 10 10 Forming:

Type Extrusion Extrusion Pressure, lbs. 20,000 Size of Shapes, I

ameter x Inches High"--. 1.125x 0.75 1. 125x0. 75 Curing:

Bed Height, Inches 3/4 3/4 Temperature of the Curing Atmosphere, F 450i10 4505110 Composition of the Curing Atmosvol. percent:

Oxygen. 21 21 Inerts 79 79 Residence Time 01 Shapes, Minutes..- 120 120 EXAMPLE VI This example involved lignite having nonagglomerating properties and of the specific species known as Sandow located at Rockdale, Texas. The analysis of the lignite was as follows.

Heating value (ash free, gross B.t.u.) 10,757

Moisture, Weight percent 25.2 Volatile matter, weight percent, dry basis 49.8 Fixed carbon, weight percent, dry basis 34.8 Ash, weight percent, dry basis 15.4 Elemental analysis, Weight percent, dry basis:

Carbon 61.3

Hydrongen 4.41 Oxygen 16.98 Nitrogen 1.25 Sulfur 1.99

Ash 14,07

As noted, the lignite was ground in a hammer mill and the finely divided lignite was then processed in the same general type of equipment as in Example I. The conditions were as indicated in Table 6, which follows:

Table 6 Catalyzing:

Length of run, hours 10. Total solids fed, lbs 54. Catalyzer, inside diameter,

inches 3.07. Temperature of fluid bed, F-- 350. Residence time, minutes 36.

Fluidizing medium- Superficial velocity, ft./sec 0.4. Composition, volume percent- Oxygen 1.2. Nitrogen 36.2. Steam 62.6. Carbonizing:

Length of run, hours 11. Total solids fed, lbs 33. Carbonizer, inside diameter,

inches 3.07. Temperature of fluid bed, F 950. Residence time, minutes 61.

Fluidizing medium Superficial velocity, ft./sec- 0.65. Composition, volume percent- Oxygen 5.2. Nitrogen Steam 36.8. Calcining:

Length of run, hours 7. Total solids fed, lbs 18. Calciner, inside diameter,

inches 3.07. Temperature of fluid bed, F 1600. Residence time, minutes 62.

Fluidizing medium Superficial velocity, ft./sec 0.7. Composition, volume percent Oxygen 11.1. Nitrogen 88.9.

21 Cooling:

Temperature of fluid bed, F Composition of fluidizing medium, vol. percent Temperature of fluidizing medi- Nitrogen (100% Temperature of blend, F .160.

Time of blend, minutes 10, Forming:

Type Extrusion. Pressure, lbs/in. 20,000. Size of shape, inches outside diameter x inches high 1.125 x 0.75. Curing:

Bed height, inches Temperature of curing atmosphere, F 400120. Composition of curing atmosphere, vol. percent- Oxygen 21. Inerts 79, Residence time of shapes, minutes 120. Coking:

Bed height, inches /1. Temperature of coking atmosphere, F 1700. Residence time, minutes 10. Composition of coking atmosphere, vol. percent- Hydrocarbons 5. Nitrogen 95. Coke yield, wt. percent of coal,

EXAMPLE VII This example involved processing of Reading Anthracite Coal having a moisture content of 4.2%, a volatile matter content (dry basis) of 4.5%, a fixed carbon content (dry basis) of 79.5%, and an ash content (dry basis) of 11.8%. All percentages are on aweight basis.

The anthracite coal was finely ground in a hammer mill to substantially the same particle size as the bituminous coals. It was then catalyzed in a catalyzer having an inside diameter of 1.5 inches by treatment in a fluid bed at a temperature of 350 F. for a residence time of 20 minutes employing a fluidizing medium containing 1.5% oxygen and 98.5% nitrogen at a superficial velocity of 0.4 foot per second.

From the catalyzing stage the catalyzed coal particles were carbonized in a carbonizer having an inside diameter of 1.5 inches by treatment in a fluid bed at a temperature of 900 F. for a residence time of 20 minutes to produce char. The fluidized medium used in this carbonizing stage was a mixture of 3.2 volume percent oxygen and 96.8 volume percent nitrogen, introduced at a superficial velocity of 0.4 foot per second.

The char was calcined in a fluid bed maintained in a calciner having an inside diameter of 1.5 inches. The temperature of the bed was 1650 F. The residence time was 20 minutes. The fluidizing medium, consisting of 100% nitrogen, was introduced into the fluid bed at a superficial velocity of 0.43 foot per second.

The calcinate was cooled to 200 F. by treatment in a fluid bed employing nitrogen as the fluidizing medium. The cooled calcinate was mixed with a coal tar pitch having a softening point of 140 F. in the proportions of 15% pitch and 85% calcinate, the temperature of the constituents being approximately 160 F. The pitch and calcinate were mixed for about 10 minutes, and then extruded under a pressure of about 20,000 pounds per square inch to produce shapes having an outside diameter of 1.125 inches and a height of 0.75 inch.

These shapes were cured by passage through a curing oven in beds inch high, in which oven was maintained a curing atmosphere consisting of 79% insert gas and 21% oxygen at a temperature of about 500 F. (:10). The residence time for the shapes in this curing oven was 2 hours.

The cured shapes were then coked in a coking bed /1 inch high at a temperature of 1700 F. in an atmosphere consisting of 95 volume percent of nitrogen and 5 volume percent of hydrocarbons (e.g., methane), for 10 minutes.

The coke yield based on the dry weight of the coal was 85 The physical and chemical properties of the coke shapes produced in Examples I to VI inclusive, are given in Table 7 which follows. In this table ASG is the apparent specific gravity at 15 .5 C. calculated from the weight and dimensions of the coked extrusions or shapes;

ED is the bulk density, in pounds per cubic foot, determined by the procedure given in ASTM D-291;

TI is the Tumbler Index determined by the procedure given in ASTM D441;

RC is the resistance to crushing in lbs/in. determined by measuring the gauge reading at which a 1% inch x inch cylinder crushed under hydraulic pressure applied to its flat surface;

MH is the Mohs Hardness index measured using the standard Mohs Hardness scale;

R is the resistivity in ohms/cmF/cm. measured using standard bridge techniques employing a test piece having a cross-sectional area of 1 cm. and a length of 1 cm.;

SAN is the surface area determined by the standard Brunauer, Emmett and Teller Method using nitrogen as the gas being absorbed;

SAW is the surface area determined by the standard Brunauer, Emmett and Teller Method using water vapor as the medium being absorbed;

AD is the absolute density as determined by Helium Sorption method;

CRCO is the reactivity in carbon dioxide measured by the amount of coke, sized to pass through a 28-mesh Tyler screen, consumed in 1 hour in a stream of carbon dioxide at 900 C. and passed over the sample at a rate of 400 ml./min.; and

CRH O is the reactivity in steam measured by the amount of coke, sized to pass through a 28-mesh Tyler screen consumed in 1 hour in a stream of steam at 825 C. and passed over the sample at a rate of 133 ml./rnin.

In both the CRCO CR-H O tests the samples were first flushed clean of air by passing argon thereover at a rate of 370 ml./ min. Each sample was crushed and screened. Particles that pass 20 mesh but lay on 30 'rnesh (U.S.S. screen size) were used. 500 milligrams weighed out on a balance of 0.1% sensitivity, were placed in a Gooch crucible cut down to fit with clearance in the silica tube of the furnace. The sample made a bed of /s" in diameter and A deep.

The chemical analyses were made by procedures outlined in the Bureau of Mines Bulletin No. 492, entitled Methods of Analyzing Coal and Coke, by A. C. Fieldner and W. A. Selvig. The values given are in weight percent on a dry basis.

VM means volatile matter; the other abbreviations under Chemical Analysis are the chemical symbols or formulae for the elements and compounds identified thereby.

C/ H is the carbon to hydrogen weight ratio. H /C is the hydrogen to carbon atom ratio.

3,140 23 For purposes of comparison, there are given in Table 7, comparative data on a high-grade commercially available by-product coke.

24- of the by-product coke, on the other hand, the product was non-uniform in character.

The chemical reactivity in air of the products produced T able 7 Commer- Tcst; Ex. I Ex. II Ex.III Ex. IV Ex. V Ex. VI Ex. VII cial By- Product Coke Physical Propcrties:

ASG 1.015 1.000 1.000 1.010 1.007 1.030 1.294 1.002 BD 38-42 37-41 30 38-42 3842 3043.5 49-54 25 T1-.- 05 93-95 95 05-08 -95 00-03 -98 05 RC 3,021 5,400 3,800 0, 950 .475 3,000 0, 000 1,000 M11. 5% 5% 5% 5% 5% 5 0 5 R. 10- 10- 10- 10- 10- 10- Microphv a Propernes:

SAN 357 1.2 70 0 1.08 1.00 Chemical activities:

The above products and the by-product coke were exor by Examples I to VI, inclusive, was determined by placing amined under a microscope at magnifications of 50X and 1 9 Shape Bunsen flame burnlng P p and 10 All of the products producfid by the pmcess f a1r in such proportlons that the blue cone was 7 cm. long this invention had an open and connected pore structure; and ended 1 8 3 1 the coke hi g T1116 in the case of the by-product coke, on the other hand, Same test g 16 3 f a? P the pore structure was open but unconnected. The procl- 40 every Case 0 6 pro 6 S 0 Xamp es o me us they were un1formly consumed and d1d not spall. In ucts produced by the process of the mventlon of Examples 1 I t VI in Iu h d ho O u e nee NO the case of by-product coke, 1t burned unevenly.

.9 2 a a 1 a d The physical and chemical properties of the calcinate V131 1 wince etween P enve 1 t e In f produced in Examples I to VII, inclusive, are given in and that denved from the calcinate was evident under thls Table 8 below The abbreviations used in this table are magnification. The product produced by the process of the Same and have the same meaning as those used in Example VII was unlform and substantlally the same Table 7, except that the apparent specific gravity was as that of the products of Examples I to VI, inclusive, exdetermined at 70 F.; the CRCO at 925 C. and the cept that it was slightly less homogeneous. In the case CRH O at 800 C.

Table 8 Test Exfixand Ex. II Ex. IV Ex.v Ex. VI Ex. V11

Physical Properties:

ASG 1.24.05

AD Chemical Reactivities:

Chemical Analysis, Moisture and Ash Free Basis:

In the case of the calcinates of Examples I to VI, inclusive, they burned rapidly and evenly in air. The calcinate from Example VII, the anthracite example, burned slowly but evenly.

Examples VIII to XI difier from Example III in that the coking of the cured shapes was carried out under the different temperatures and curing times give in Table 9 using the same inert coking atmosphere in all examples. These examples show the effects of higher coking temperatures and longer coking times on the cured shapes and demonstrate that by coking the cured shapes at temperatures in excess of 1750 F., say at 2500 F. to 4000 F., for a long enough period of time, the length of which is inversely proportional to the temperature, products of low chemical reactivity and high strength result.

Table 9 Ex. VIII Ex. IX Ex. X Ex. XI

COKING:

Bed Height, inches 72 72 72 72 Temperature of Coking Atmosphere, F 1, 687 1,875 2, 500, 4, 000 Residence Time, minutes 57 720 480 90 Table 10 Ex. VIII EX.IX Ex.X Ex.XI

011-002 15.0 4.6 2.0 0.8 (JR-H2O 1s. 9. 9 a. 2 1. 2

All of the products were of high strength. The RC (resistance to crushing) value of the product of Example III was 3800. This product had a crushing strength of 170 lbs., determined by ascertaining the number of pounds pressure required to crush a A; x /2 X inch pillow between jaws. Employing the same test procedure the crushing strength of the product of Example VIII was 185, of Example IX was 195, of Example X was 210 and of Example XI was 110.

It will be noted that the present invention provides a process for treating coals of any rank, in particular the cheap, widely available coals of non-coking quality, to produce a physically strong, carbonaceous product possessing essentially the same structure and apparent density as the parent coal. The process of this invention may be practiced to produce chemically reactive carbonaceous products suitable for use, among other uses, as a metallurgical carbon. The process of the present invention may also be carried out to produce carbonaceous products of high strength and having controlled chemical reactivity; thus, products of different reactivities from highly reactive (many times that of high temperature byproduct coke) to comparatively inert material and having desired predictable physical characteristics can be produced.

It will be further noted that the present invention can be used to produce calcinate which is remarkably strong, abrasive-resistant, homogeneous, and exceptionally uniform in reaction with carbon dioxide, steam and oxygen. This calcinate can be used as such, for example, as a raw material for water gas or other gas reactions in the place of coal or coke, or for eifecting the reduction of ores, as in sintered iron processes. It can be combined with a binder and the mixture compressed to produce a dense unit of any desired shape or size which is cured and coked as hereinabove disclosed to produce coke shapes possessing qualities rendering them eminently satisfactory for such uses as smelting of phosphorus and other ores, and carrying out chemical reactions. By processing under conditions herein disclosed, a high strength product of low chemical reactivity results; such products are suitable, among other uses, as a structural material in the chemical field.

All percentages in this specification, unless otherwise indicated, are on a weight basis.

Since certain changes may be made in carrying out the above described method without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A process of producing carbonaceous material which comprises heating non-coking coal particles to a temperature within the range of 250 F. to 500 F. in an atmosphere containing from 1% to 8% by-volume of oxygen for from 5 minutes to 3 hours to produce catalyzed coal particles conditioned so that in the next heating stage the content of hydrocarbonaceous matter in the coal is reduced; heating the catalyzed coal particles to a still higher temperature but not exceeding 1200 F. and maintaining them at said higher temperature for from 10 to 60 minutes to evolve vapors and produce char which has a markedly lower volatile combustible material content than the parent coal; and heating the char to a still higher temperature within the range of from 1400 F. to 1800 F. and maintaining the heated char at said higher temperature for a time interval to produce calcinate.

2. A process of producing carbonaceous shapes which comprises heating coal particles in the presence of from 1% to 20% by volume of oxygen to a temperature above 250 F. and below that at which substantial amounts of tar-forming vapors evolve for a time interval sufficient to reduce the water vapor content of the coal particles to not exceeding 2% by weight and produce catalyzed coal particles; heating the catalyzed coal particles to a still higher temperature and maintaining them at said higher temperature for a time interval sufficient to evolve substantially all tar-forming vapors in the catalyzed coal particles and produce char; heating the char to a still higher temperature and maintaining the heated char at said higher temperature for a time interval sufficient to produce hot calcinate; cooling said hot calcinate particles; blending said cooled calcinate particles with a bituminous binder; subjecting said blend to pressure to produce green shapes; curing the green shapes thus produced in an atmosphere containing oxygen to copolymerize the bituminous binder with the calcinate particles, without coking the binder, to produce cured shapes; coking the cured shapes; and cooling the coked shapes.

3. A process of producing carbonaceous shapes which comprises heating coal particles in the presence of from 1% to 20% by volume of oxygen to a temperature above 250 F. and below that at which substantial amounts of tar-forming vapors evolve for a time interval suflicient to reduce the water vapor content of the coal particles to not exceeding 2% by weight and produce catalyzed coal particles; heating the catalyzed coal particles to a still higher temperature and maintaining them at said higher temperature for a time interval suflicient to evolve substantially all tar-forming vapors in the catalyzed coal particles and produce char; heating the char to a still higher temperature and maintaining the heated char at said higher temperature for a time interval sufficient to produce hot calcinate having a volatile combustible material content not exceeding about 3% by weight, on a moisture and ash free basis; substantially instantaneously cooling said hot calcinate particles to a temperature of from 30 F. to 60 F. above the softening point of the binder used in the subsequent blending stage of the process; blending said cooled calcinate particles with a bituminous binder having a softening point within the range of 100 F. to 225 F. in the proportions of 75% to 90% by weight of calcinate to 10% to 25 by weight of binder; subjecting the blend to a forming pressure to produce green shapes; curing the green shapes thus produced in an atmosphere containing from 2.5% to 21% by volume of oxygen at a temperature of from 450 F. to 500 F. for 90 to 180 minutes; coking the cured shapes at a temperature above 1500 F.; and cooling the coked shapes to a temperature below 500 F.

4. A process of producing carbonaceous shapes which comprises heating non-coking coal particles to a temperature within the range of 250 F. to 500 F. in an atmosphere containing from 1% to 8% by volume of oxygen for from 5 minutes to 3 hous to produce catalyzed coal particles conditioned so that in the next heating stage the hydrocarbonaceous matter is reduced; heating the catalyzed coal particles to a still higher temperature but not exceeding 1200 F. and maintaining them at said higher temperature for from 10 to 60 minutes to evolve vapors and produce char which has a markedly lower volatile combustible material content than the parent coal; heating the char to a still higher temperature within the range of from 1400 F. to 1800 F. and maintaining the heated char at said higher temperature to produce hot calcinate having a volatil combustible material content not exceeding about 3% by weight, on a moisture and ash free basis; and cooling said hot calcinate particles to a temperature above the softening point of the binder used in the subsequent blending stage of the process; blending said cooled calcinate particles with a bituminous binder having a softening point within the range of 100 F. to 225 F. in the proportions of 75% to 90% by weight of calcinate to 10% to 25% by weight of binder; subjecting the resultant blend to a forming pressure to produce green shapes; curing the green shapes thus produced in an atmosphere containing from 2.5 to 21 by volume of oxygen at a temperature of from 450 F. to 500 F. for 90 to 180 minutes; coking the cured shapes at a temperature above 1500 F. and cooling the coked shapes to a temperature below 500 F.

5. A process of producing carbonaceous shapes which comprises heating coking coal particles to a temperature within the rang of 500 F. to 800 F. in an atmosphere containing from 8% to 20% by volume of oxygen for from minutes to 3 hours to produce catalyzed coal particles conditioned so that in the next heating stage the content of hydrocarbonaceous matter in the coal is reduced; heating the catalyzed coal particles substantially instantaneously to a still higher temperature but not exceeding l200 F. and maintaining them at said higher temperature for from 10 to 60 minutes to evolve vapors and produce char which has a markedly lower volatile combustible material content than the parent coal; heating the char to a still higher temperature within the range of from 1400 F. to 1800 F. and maintaining the heated char at said higher temperature to produce hot calcinate having a volatile combustible material content not exceeding 3% by weight; substantially instantaneously cooling said hot calcinate particles to a temperature above the softening point of the binder used in the susequent blending stage of the process; blending said cooled calcinate particles with a bituminous binder having a softening point within the range of 100 F. to 225 F. in the proportions of 75% to 90% by weight of calcinate to 10% to 25 by weight of binder; subjecting the blend to a forming pressure to produce green shapes; curing the green shapes thus produced in an atmosphere containing from 2.5% to 21% by volume of oxygen at a temperature of from 450 F. to 500 F. for 90 to 180 minutes to produce cured shapes; coking the cured shapes at a temperature above 1500 F.; and cooling the coked shapes to a temperature below 500 F.

6. The method of producing chemically reactive carbonaceous material from non-coking bituminous coals which comprises heating for 5 minutes to 3 hours noncoking bituminous coal particles in an atmosphere containing from 1% to 8% by volume of oxygen to a temperature of from 250 F. to 500 F.; thereafter further heating the thus treated coal particles substantially instantaneously to a temperature of from 500 F. to l200 F. and maintaining the coal particles at said temperature for from 10 to 60 minutes; and thereafter substantially instantaneously heating the thus treated coal particles to a temperature of from 1400 F. to 1800 F. in an atmosphere substantially free of carbon dioxide and water vapor and maintaining them at said temperature for a time interval suflicient to reduce the volatile content to a maximum of about 3% by weight, on a moisture and ash free basis.

7. The method of producing physically strong, chemically reactive carbonaceous material from non-coking coals involving heating the non-coking coal particles in a first fluidized bed in an atmosphere containing from 1% to 8% by volume of oxygen to a temperature of from 250 F. to 500 F. for from 5 minutes to 3 hours; removing the thus heated coal particles from said first mentioned fluidized bed and introducing them into a second fluidized bed where they are heated to a temperature of from 500 F. to 1200 F. for from 10 to 60 minutes, said heating being effected in part at least by combustion of a portion of the coal; removing the thus heated coal particles from the second fluidized bed and introducing them into a third fluidized bed where they are heated to a temperature of from 1400 F. to 1800 F. for from 7 to 60 minutes in a fluidizing gas atmosphere consisting of flue gas substantially free of carbon dioxide, oxygen and water vapor; and thereafter withdrawing the thus heated finely divided coal particles and introducing them into a fourth fluidized bed where they are cooled by a fluidizing flue gas medium substantially free of carbon dioxide, oxygen and water vapor.

8. The method of producing physically strong, chemically reactive carbonaceous shapes from coal, which comprises heating coal particles in an atmosphere containing from 1% to 20% by volume of oxygen to a temperature of from 250 F. to 800 F. for a time interval suflicient to produce catalyzed coal particles conditioned so that in the next heating stage the content of hydrocarbonaceous matter in the coal is reduced; thereafter substantially instantaneously heating the catalyzed coal particles to a still higher temperature but not exceeding l200 F. for a time interval suflicient to evolve vapors and produce char which has a markedly lower volatile combustible material content; thereafter substantially instantaneously heating the char to a temperature of from 1400" F. to 1800 F. in an atmosphere substantially free of carbon dioxide and water vapor and maintaining them at said temperature to produce hot calcinate; then cooling the hot calcinate; mixing the cooled calcinate with a bituminous binder in the proportions of 75% to by weight of calcinate to 10% to 25% by weight of binder; compressing the resultant mixture to produce green shapes; curing the green shapes by passing them through a heating zone at a temperature of from 450 F. to 500 F. in an atmosphere containing from 2.5% to 21% by volume of oxygen for from 90 minutes to 3 hours to produce cured shapes; and coking the cured shapes to reduce the volatile content to not exceeding 3% by weight in an atmosphere substantially free of carbon dioxide, water vapor and oxygen at a temperature of from 1500 F. to 1750 F.

9. The method of producing physically strong, chemically reactive carbonaceous shapes from non-coking coals, which comprises heating for 5 minutes to 3 hours non coking bituminous coal particles in an atmosphere containing from 1% to 8% by volume of oxygen to a temperature of from 250 F. to 500 F; thereafter further heating the thus treated coal particles substantially instantaneously to a temperature of from 500 F. to 1200 F. and maintaining the coal particles at said temperature for from 10 to 60 minutes; thereafter substantially instantaneously heating the thus treated coal to a temperature of from 1400 F. to 1800 F. in an atmosphere substantially free of carbon dioxide and water vapor and maintaining them at said temperature for from 7 to 60 minutes to reduce the volatile content to a maximum of about 3% by weight, on a moisture and ash free basis; then cooling the thus treated coal particles substantially instantaneously to a temperature below 400 F.; mixing the cooled coal particles with a bituminous binder in the proportions of 75% to 90% by weight of coal particles to 10% to 25% by weight of binder; compressing the resultant mixture to produce green shapes; curing the green shapes by passing them through a heating zone at a temperature of from 450 F. to 500 F. in an atmosphere containing from 2.5% to 21% by volume of oxygen for from 90 to 180 minutes to produce cured shapes; and coking the cured shapes to reduce the volatile content to not exceeding 3% by weight in an atmosphere substantially free of carbon dioxide, water vapor and oxygen at a temperature of from 1500 F. to 1750 F. for from 5 to 60 minutes.

10. The method of producing physically strong, chemically reactive carbonaceous shapes from coking coals, which comprises heating coal particles in a fluidized bed to a temperature of from 500 F. to 800 F. in an atmosphere containing from 8% to 20% by volume of oxygen; heating the thus treated coal particles for from to 60 minutes to a still higher temperature by introducing them into and maintaining them in a fluidized bed at a temperature not exceeding 1200 F.; thereafter heating the thus treated coal particles in another fluidized bed to a temperature of from 1400 F. to 1800 F.; maintaining the coal particles in said last mentioned fluidized bed for from 7 minutes to 1 hour to reduce the volatiles in said coal to below about 3% by weight, on a moisture and ash free basis; cooling the thus heated coal particles to a temperature below 400 F.; mixing the cooled coal particles with a bituminous binder in the proportions of 75% to 90% by weight of coal particles to 10% to 25% by weight of binder; compressing the resultant mixture to produce green shapes; curing the green shapes by passing them through a heating zone at a temperature of from 450 F. to 500 F. in an atmosphere containing from 2.5% to 21% by volume of oxygen for from 90 to 180 minutes to produce cured shapes; and coking the cured shapes to reduce the volatile content to not exceeding 3% by weight in an atmosphere substantially free of carbon dioxide, water vapor and oxygen at a temperature of from 1500 F. to 1750 F.

11. The method of producing physically strong, chemically reactive carbonaceous briquettes from coal, which comprises heating non-coking coal particles in a first fluidized bed in an atmosphere containing from 1% to 8% by volume of oxygen to a temperature of from 250 F. to 500 F said coal particles being subjected to said heating in said fluidized bed for an average residence time of at least 5 minutes; removing the thus heated coal particles from said first mentioned fluidized bed and introducing them into a second fluidized bed where they are heated to a temperature of from 500 F. to 1200 F. for from 10 to 60 minutes; introducing the fluidizing gas into the second fluidized bed at a temperature not below and within 20 F. of the bed temperature; removing the thus heated coal particles from the second fluidized bed and introducing them into a third fluidized bed where they are subjected to a temperature of from 1400 F. to 1800 F. in an atmosphere substantially free of carbon dioxide and water vapor; thereafter withdrawing the thus heated coal particles and introducing them into a fourth fluidized bed where they are cooled by the fluidizing medium to a tempertaure not exceeding 400 F., said cooling medium being substantially free of carbon dioxide, oxygen and water vapor; mixing the cooled carbonaceous material with a bituminous binder having a softening point of 100 F. to 225 F. in the proportions of 75% to by weight of carbonaceous material to 10% to 25% by weight of binder at a temperature from 30 F. to 60 F. above the softening point of said binder; briquetting the resultant mixture; curing the briquettes by passing them through a heating zone at a temperature of from 450 F. to 500 F. in an atmosphere containing from 2.5% to 21% by volume of oxygen; and coking the thus cured briquettes to reduce the volatile content to not exceeding about 3% by weight, on a moisture and ash free basis, in an atmosphere substantially free of carbon dioxide, water vapor and oxygen at a temperature of from 1500 F. to 1750 F.

12. The method of producing physically strong, carbonaceous briquettes from coal, which comprises heating coal particles in a first fluidized bed in an atmosphere containing from 1% to 20% oxygen to a temperature of from 250 F. to 800 F. for from 5 minutes to 3 hours; removing the thus heated coal particles from said first mentioned fluidized bed and introducing them into a second fluidized bed where they are heated to a temperature not exceeding 1200 F. for from 10 to 60 minutes, said heating being effected in part at least by combustion of a portion of the coal; introducing fluidizing flue gas into the second fluidized bed at a temperature not less than that of the bed temperature; removing the thus heated coal particles from the second fluidized bed and introducing them into a third fluidized bed where they are heated to 1400 F. to 1800 F. for from 7 minutes to 1 hour in a fluidizing gas atmosphere consisting of flue gas substantially free of carbon dioxide and water vapor; thereafter withdrawing the thus heated coal particles and introducing them into a fourth fluidized bed Where they are cooled by a fluidizing flue gas medium to a temperature not exceeding 400 F., said cooling medium being substantially free of carbon dioxide, oxygen and water vapor; mixing the cooled carbonaceous material with a bituminous binder in the proportions of 75% to 90% by weight of reactive carbonaceous material to 10% to 25 by weight of binder; briquetting the resultant mixture; curing the briquettes by passing them through a heating zone at a temperature of from 450 F. to 500 F. in an atmosphere containing from 2.5 to 21 by volume of oxygen, maintaining the briquettes in said zone for from 90 to 180 minutes to produce cured briquettes; and coking the thus cured briquettes to reduce the volatile content to not exceeding about 3% by weight, on a moisture and ash free basis, in an atmosphere substantially free of carbon dioxide, water vapor and oxygen at a temperature of from 1500 F. to 4000 F. for a time interval suflicient to produce coked shapes having the desired chemical reactivity.

13. The process as defined in claim 12, in which the bituminous binder is obtained from the tar condensed out of the gases evolved during the heating of said coal particles in the second mentioned fluidized bed and has a softening point of from F. to 225 F.

14. A method for. the conversion of coals of any rank from anthracite to lignite into pitch-bonded carbon products possessing high mechanical strength, which method comprises the following steps: step 1, heating the coal in pulverized form in a mildly oxidizing atmosphere at a temperature below that at which substantial amounts of tar-forming vapors evolve and above that at which water, when present, vaporizes, to produce a product which is non-agglomerating in step 2; step 2, heating the product of step 1 to a temperature at which evolution of tar-forming vapors takes place at a rate insuificient to cause permanent swelling, distortion and disruption of the product of step 1, said heating being for a time interval long enough to effect substantially complete removal of tar-forming vapors and materially reduce the volatile matter but not long enough to impair the pyrophoric reactivity of the product of step 2; step 3, heating the product of step 2 to amazes a temperature not exceeding 1800 F. in an atmosphere containing only sufiicient oxygen for the coal particles to reach said heating temperature and for a period of time to effect reduction of the volatile content of the product of step 2 to less than about 3% by Weight, on a moisture and ash free basis, without substantial impairment of the pyrophoric reactivity of the product of step 3; step 4,

lending the product of step 3 with pitch in amount suflicient to coat the product of step 3 and produce a mechanically strong product when subjected to compression; step 5, compressing the blended product of step 4; step 6, curing the compressed product of step by rapid heating in a mildly oxidizing atmosphere at a temperature sufiicient to cause copolyrnerization of the pitch binder and the product of step 3 to take place; and, step 7, coking the product of step 6 at a temperature exceeding 1500 F. in an inert atmosphere for a time interval to produce a high strength product having the desired chemical reactivity.

15. A method for the conversion of coals of any rank from anthracite to lignite into pitch-bonded carbon products possessing high mechanical strength and high chemical reactivity, which method comprises the following steps; step 1, heating the coal in pulverized form in a mildly oxidizing fluidizing atmosphere at a temperature below that at which substantial amounts of tar-forming vapors evolve and above that at which water, when present, vaporizes, to produce a product which is non-agglomerating in step 2; step 2, heating the product of step 1 in a fiuidizing atmosphere containing oxygen to a temperature causing evolution substantially all of tar-forming vapors at a rate insufiicient to cause permanent swelling, distortion and disruption of the Product of step 1, said heating being for a time interval long enough to materially reduce the volatile matter but not long enough to impair the pyrophoric reactivity of the product of step 2; step 3, heating the product of step 2 to a temperature not exceeding 1800 F. in a fluidizing atmosphere containing only sufficient oxygen for the coal particles to reach said heating temperature and for a period of time to effect reduction of the volatile content of the product of step 2 to less than about 3% by weight, on a moisture and ash free basis, without substantial impairment of the pyrophoric reactivity of the product of step 3; step 4, blending the product of step 3 with pitch in amount sufficient to coat the product of step 3 and produce a mechanically strong product when subjected to compression; step 5, compressing the blended product of step 4; step 6, curing the compressed product of step 5 by rapid heating in a mildly oxidizing atmosphere at a temperature below that at which coking of the pitch binder takes place but sutficient to cause copolymerization of the pitch binder and the product of step 3 to take place; and, step 7, heating the product of step 6 to a temperature not exceeding 1750 F. in an inert atmosphere to produce a coke product of high mechanical strength and high chemical reactivity.

16. A method for the conversion of coals of any rank from anthracite to lignite into pitch-bonded carbon products possessing high mechanical strength, which method comprises the following steps: step 1, heating the coal in pulverized form in a mildly oxidizing fiuidizing atmosphere at a temperature below that at which substantial amounts of tar-forming vapors evolve and above that at which water, when present, vaporizes, to produce a product which is non-agglomerating in step 2; step 2, heating the product of step 1 in a fiuidizing atmosphere containing oxygen to a temperature causing evolution substantially all of tar-forming vapors at a rate insufficient to cause permanent swelling, distortion and disruption of the product of step 1, said heating being for a time interval long enough to materially reduce the volatile matter but not long enough to impair the pyrophoric reactivity of the product of step 2; step 3, heating the product of step 2 to a temperature not exceeding 1800 F. in a fiuidizing atmosphere containing only suflicient oxygen for the coal particles to reach said heating temperature and for a period of time to effect reduction of the volatile content of the product of step 2 to less than about 3% by weight, on a moisture and ash free basis, without substantial impairment of the pyrophoric reactivity of the product of step 3; step 4, blending the product of step 3 with pitch in amount sufiicient to coat the product of step 3 and produce a mechanically strong product when subjected to compression; step 5, compressing the blended product of step 4; step 6, curing the compressed product of step 5 by rapid heating in a mildly oxidizing atmosphere at a temperature below that at which coking of the pitch binder takes place but sufiicient to cause copolymerization of the pitch binder and the product of step 3 to take place; and, step 7, heating the product of step 6 to a temperature within the range of 1750 F. to 4000 F. for a time interval to produce a high strength product of low chemical reactivity.

17. The method as defined in claim 14 in which in step 5 the blended product of step 4 is heated to a temperature not exceeding 50 F. below the coking point of the pitch binder.

18. The process of producing carbonaceous shapes which comprises the following steps: step 1, heating coal particles in the presence of oxygen to a temperature above 250 F. and below that at which substantial amounts of tar-forming vapors evolve to produce a product which is non-agglomerating in step 2; step 2, heating the product of step 1 to a higher temperature at which tar-forming vapors are evolved, and maintaining said heated particles at said higher temperature for a time interval suflicient to effect polymerization of the heated coal particles and evolution therefrom of substantially all vapors which condense as tars, producing a char of markedly lower volatile combustible material content than the parent coal and substantially free of tar-forming vapors; step 3, heating the char of step 2 to a still higher temperature for a time interval sufiicient to produce calcined char particles; step 4, cooling the product of step 3; step 5, blending said cooled product from step 4 with a bituminous binder; step 6, compressing said blend to produce green shapes; step 7, curing the green shapes in an oxidizing atmosphere at a temperature below that at which coking of the bituminous binder takes place but sufficient to effect copolymerization of the bituminous binder with the char particles; step 8, coking the cured shapes; and step 9,

cooling the coked shapes.

19. The process of producing carbonaceous shapes which comprises heating coal particles in the presence of from 1% to 20% by volume of oxygen to a temperature above 250 F. and below that at which substantial amounts of tar-forming vapors evolve for a time interval suflicient to produce catalyzed coal particles; heating the catalyzed coal particles to a still higher temperature at which tar-forming vapors are evolved and maintaining said heated particles at said higher temperature for a time interval sufiicient to effect polymerization of the heated coal particles and evolution therefrom of substantially all tar-forming vapors, producing a char of markedly lower volatile combustible material content than the parent coal and substantially free of tar-forming vapors; heating the char to a still higher temperature and maintaining said heated char at said higher temperature for a time interval sufficient to produce calcined char particles; cooling said calcinate particles; blending said cooled calcinate particles with a bituminous binder; compressing said blend to produce green shapes; curing the green shapes in an oxidizing atmosphere at a temperature below that at which coking of the bituminous binder takes place but sufiicient to effect copolymerization of the bituminous binder with the char particles; coking the cured shapes and cooling the coked shapes.

20. The process of producing carbonaceous shapes as defined in claim 19, in which the green shapes are cured at a temperature not exceeding 50 F. below the coking point of the bituminous binder.

21. The process of producing carbonaceous material which comprises the following steps: step 1, heating coal particles in the presence of oxygen to a temperature above 250 F. and below that at which substantial amounts of tar-forming vapors evolve; step 2, heating the product of step 1 to a higher temperature at which tar-forming vapors are evolved, and maintaining said heated particles at said higher temperature for a time interval sufficient to eflfect polymerization of the heated coal particles and evolution therefrom of substantially all of said tar-forming vapors, producing a char of markedly lower volatile combustible material content than the parent coal and substantially free of tar-forming vapors; and step 3, separately removing the tar-forming vapors evolved in step 2 and the char produced in step 2 and heating the char produced in step 2 out of contact with said tarforming vapors evolved in step 2 to a still higher temperature for a time interval sufiicient to produce calcined char particles.

22. The process of producing carbonaceous material which comprises heating coal particles in the presence of from 1% to 20% by volume of oxygen to a temperature above 250 F. and below that at which substantial amounts of tar-forming vapors evolve for a time interval sufiicient to produce catalyzed coal particles conditioned so that in the subsequent carbonizing stage the hydrocarbonaceous content is reduced; heating the catalyzed coal particles to a still higher temperature at which vapors which condense as tars are evolved and maintaining said heated particles at said higher temperature for a time interval sufficient to effect polymerization of the heated coal particles and evolution therefrom of substantially all vapors which condense as tars, producing a char of markedly lower volatile combustible material content than the parent coal and substantially free of tar-forming vapors; and separately removing all vapors which condense as tars and said char from the preceding heating step and heating the char thus removed out of contact with the tar-forming vapors evolved in the preceding step to a still higher temperature and maintaining said heated char while thus heated at the higher temperature for a time interval suflicient to produce calcined char particles having a volatile combustible material content below about 3 by weight.

23. The process for the rapid step-wise devolatilization of coal to produce a char of high chemical reactivity without substantial destructive deformation of the original coal particles, which process comprises the following steps: step 1, rapidly heating the coal particles in an oxygen-containing atmosphere to a temperature (1) above 250 F. and (2) below the temperature at which substantial amounts of tar-forming vapors evolve, the temperature being such as to avoid destructive deformation of the coal particles and to produce pyrophorically active char particles upon treatment in the subsequent steps of the process; step 2, rapidly heating the product of step 1 to a temperature to cause evolution of condensible tar vapors at a rate insufiicient to cause destructive deformation of the coal particles and continuing said heating until said evolution of condensible tar-forming vapors is substantially complete thereby producing a pyrophoric char substantially free of tar-forming vapors; step 3, separately removing the condensible tar-forming vapors formed in step 2 and the char produced in step 2 and heating the char produced in step 2 out of contact with said tarforming vapors evolved in step 2 to a still higher temperature to produce calcined char particles having a volatile combustible material content below about 3% by weight of the char particles as produced in step 3; and step 4, cooling the products of step 3 to below 400 F. in an inert atmosphere to produce calcined char particles having uniform homogeneous structure and high chemical reactivity.

24. The process of producing carbonaceous material which comprises the following steps: step 1, heating coal particles in the presence of oxygen to a temperature above 250 F. and below that at which substantial amounts of tar-forming vapors evolve to produce a product which is non-agglomerating in step 2; step 2, heating the product of step 1 to a higher temperature at which tar-forming vapors are evolved, and maintaining said heated particles at said higher temperature for a time interval suflicient to effect polymerization of the heated coal particles and evolution therefrom of substantially all vapors which condense as tars, producing a char of markedly lower volatile combustible material content than the parent coal and substantially free of tar-forming vapors; and step 3, separately removing the tar-forming vapors evolved in step 2 and the char produced in step 2 and heating the char produced in step 2 out of contact with said tar-forming vapors evolved in step 2 to a still higher temperature not exceeding 1800 F. for a residence time not exceeding ten minutes to produce calcined char particles having a volatile combustible material content below about 3% by weight based on the weight of the calcined char as produced in step 3.

References Cited in the file of this patent UNITED STATES PATENTS 1,943,291 Abbott Jan. 16, 1934 2,164,933 Maurel July 4, 1939 2,582,712 Howard Ian. 15, 1952 2,734,851 Smith Feb, 14, 1956 2,805,189 Williams Sept. 3, 1957 2,815,316 Kruppa et al Dec. 3, 1957 2,869,992 Brown et al. Jan. 20, 1959 3,001,237 Balaguer Sept. 26, 1961 3,018,227 Baum et al Jan. 23, 1962 3,051,629 Gorin et al. Aug. 28, 1962 3,070,515 Sylvander Dec. 25, 1962 FOREIGN PATENTS 153,801 Australia Oct. 23, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No., 3,14o 241 Julyfl 1964 Josiah Work etfaL- It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column l line "62 for "'Thees" read:i a'l'fhese -zg' 'col'umn I Y line 2, for "dimension" read dimensions line 33: for "not" read now '-'-3 line 44 for "reading read 1:-e'ad1 .Iy column ll line 73 for "of read or ---;;.1 column 12 lines 13 and 14 for "'non-exidizing' read now-oxidizing column l5. line l6 for gat read gas column l8 I line I? for 1 4900 read 12 line 18 for "120" read 1 4900 --g column l9 Table 5 line 53 thereof for "Outside of Di-- read Outside Dr -"=5 column 2O line 2'? for ""Hydrongen read Hydrogen column 21 line 1O for 140 read 140 F. column 22 line l0 for "insert" read inert I! column 2'? line 16 for ""hous read hours line 29 strike out "andfl second occurrencea line 46 for rang read range. column 29 line 75 for 'tempertaure" read. temperature column 31 line 31 and lines 67 and 68 for "evolution substantially all 013" each occurrence read evolution of substantially all -o Signed and sealed this 10th day of November 1964,

(SEAL) Attest:

ERNEST W0 SWIDER EDWARD Ja BRENNER Attesting Officer Commissioner of Patents

Claims (1)

1. A PROCESS OF PRODUCING CARBONACEOUS MATERIAL WHICH COMPRISES HEATING NON-COKING OF 250*F. TO 500*F. IN AN ATMOSPHERE CONTAINING FROM 1% TO 8% BY VOLUME OF OXYGEN FOR FROM 5 MINUTES TO 3 HOURS TO PRODUCE CATALYZED COAL PARTICLES CONDITIONED SO THAT IN THE NEXT HEATING STAGE THE CONTENT OF HYDROCARBONACEOUS MATTER IN THE COAL IS REDUCED; HEATING THE CATALYZED COAL PARTICLES TO A STILL HIGHER TEMPERATURE BUT NOT EXCEEDING 1200*F. AND MAINTAINING THEM THEM AT SAID HIGHER TEMPERATURE FOR FROM 10 TO 60 MINUTES TO EVOLVE VAPORS AND PRODUCE CHAR WHICH HAS A MARKEDLY LOWER VOLATILE COMBUSTIBLE MATERIAL CONTENT THAN THE PARENT COAL; AND HEATING THE CHAR TO A STILL HIGHER TEMPERATURE WITHIN THE RANGE OF FROM 1400* F. TO 1800*F. AND MAINTAINING THE HEATED CHAR AT SAID

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