US3619376A - Method of making metallurgical coke briquettes from coal, raw petroleum coke, inert material and a binder - Google Patents

Abstract

The process comprises: mixing selected carbonaceous particles with a plasticizer; heating the particles and the plasticizer to a suitable temperature; compressing the plasticized particles while they are hot into green bodies of desired shape and specified maximum porosity and minimum density; and carbonizing the formed green bodies, employing a controlled carbonization process. Care it taken to avoid any substantial amount of oxidation of the particles and/or of the formed green bodies during most of the aforesaid heating, pressing and carbonizing steps, particularly while the particles or bodies are at substantially elevated temperatures. Other elements of the process will become apparent from a detailed reading of this specification.

Description

United States Patent [72] Inventor Joseph J- Patel 2,808,370 10/1957 Bowers 201/22 Skokie, 111.; 3,010,882 11/1961 Barclaet a1 201/6 U X Frederick L. Shea, Jr., Johnson City, 3,018,227 1/1962 Baum et a1 201/23 Tenn.; Richard L. Stec, Chicago, 111. 3,018,226 l/ 1962 Batchelor et a1 201/5 [21] Appl. No. 630,373 3,316,155 4/1967 Holowaty et a1 201/6 grai Primary Exammer--Norman Yudkoff 73] Assignee Great Lakes Carbon Corporation Asmmm Edwards New York, NY. Anorneya ace eyer m [54] METHOD OF MAKING METALLURGICAL COKE BRIQUETTES FROM COAL, RAW PETROLEUM ABSTRACT: The process comprises: mrxmg selected car- COKE, INERT MATERIAL AND A BINDER bonaceous particles wlth a plastlcrzer; heating the particles 30 Claims 3 Drawing Figs. and the P13916126! to a suitable temperature; compressing the plastlclzed particles while they are hot Into green bodies of [52] US. Cl 201/6, desired shape and ifi d maximum porosity and minimum 2on8 201/22' 201mg 264/29 density; and carbonizing the formed green bodies, employing [511 int. Cl ClOb 55/02 a controlled carbonization process Cal-e it taken to avoid any [50] Field of Search 201/5, 6, 7, Substantial] amount f oxidation f the panicles and/or f the 8, 21-24, 34, 42; 264/29; 44/ 23 formed green bodies during most of the aforesaid heating, pressing and carbonizing steps, particularly while the particles [56] References Cited or bodies are at substantially elevated temperatures. Other UNITED STATES PATENTS elements of the process will become a arent from a detailed PP 2,336,151 12/1943 Kruppa 201/6 X reading ofthis specification.

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BITUMINOUS COAL OR PARTIALLY DEVOLATILIZED BITUMINOUS COAL HAVING A VM OF AT LEAST I5% LEAST 8% COKE BREEZE 6 z I iz Q 0| 4, 0 "*0 6 BLEND,(IF NECESSARY) CRUSH TO AT LEAST SUBSTANTIALLY IOO/ MINUS INCH PARTICLE SIZE, OPTIONALLY DRYING THE STARTING MATERIALIS) BEFORE 0R AFTER BLENDING AND MILLING.

HEAT PARTICLES T0 TEMPERATURE BELOW THEIR FUSION TEMPERATURE BUT TO A TEMPERATURE AT LEAST AS HIGH AS ABOUT 300 F, BY HEATING IN AN INERT GAS SYSTEM.

REMOVE PARTICLES FROM HEATER,MAI AN INERT ATMOSPHERE.

NTAINING BUT BELOW THE FUSION TEMPERATURE PARTICLES OF THE BASE MATERIALIS).

OF THE GREATER THAN 37 l BRIQUET OR PRESS THE PLASTICIZED MIX WHILE IT IS STILL ABOVE ABOUT 300F TYPICALLY LIMITING THE RETENTION TIME AT MAXIMUM TEMPERATURE PRIOR TO PRESSING TO 5 MINUTES, EMPLOYING PRESSURES ABOVE 500 PSI AND PRESSING TIMES TYPICALLY LESS THAN 2 SECONDS, TO PRODUCE FORMED GREEN BODIES WHICH HAVE A.D. OF AT LEAST 0.85 AND A POROSITY NO EMPLOYING A RAPID CAR (8 HOURS OR LESS) CARBONIZE THE FORMED GREEN BODIES,WITHOUT SUBSTANTIAL COOLING TO A LOW VM CONTENT;

BONIZATION PROCESS.

PAIENTEDunv 9 |97I RAW PETROLEUM COKE HAVING A VM OF AT LEAST 8/o SHEET 3 BF 3 I INERT MATERIAL SUCH I AS ANTHRACITE OR I COKE BREEZE J BITUMINOUS COAL OR PARTIALLY DEVOLATILIZED BITUMINOUS COAL HAVING A VM OF AT LEAST |5/o BLEND,(IF NECESSARY) CRUSH TO AT LEAST SUBSTANTIALLY IOO/o MINUS V8 INCH PARTICLE SIZE, OPTIONALLY DRYING THE STARTING (S) BEFORE OR AFTER BLENDING AND MIX PARTICLES WITH I-8 PPH OF PLASTICIZER AND HEAT SAID MIXTURE TO A TEMPERATURE AT LEAST AS HIGH AS ABOUT 300F BUT BELOW THE FUSION TEMPERATURE OF THE PARTICLES OF THE BASE MATERIAL(S).

CARBONIZE THE FORMED GREEN BODIES,WITHOUT SUBSTANTIAL COOLING, TO A LOW VM CONTENT; EMELOYING A RAPID CARBONIZATION PROCESS. (8 HOURS OR LESS) FIE. 3

METHOD OF MAKING METALLURGICAL COKE BRIQUE'I'IES FROM COAL, RAW PETROLEUM COKE, INERT MATERIAL AND A BINDER BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to a novel process for producing coke suitable for use in cupolas, blast furnaces and other metallurgical operations.

2. Description of the Prior Art Typically the prior art cokes suitable for the above purposes have been produced in byproduct coking ovens by coking a blend of high and low-volatile bituminous coals, or by coking a blend of such coals along with other suitable ingredients such as pitch and anthracite; the types, number and amounts of the components having been selected according to the ultimate properties desired in the coke. The size and strength of the coked product has been nonuniform-so that some of the product has been of desired size and strength; some has been of the desired size but of inferior strength as indicated by poor shatter and tumbler values; some as been undersize, etc. Such variations make good cupola operation difficult, particularly where large volume production is concerned or where close limits in metal composition and temperature are necessary, such as when castings are being made for critical applications.

SUMMARY OF THE INVENTION It is an object of the present invention to produce a metallurgical coke by a technique completely different from the aforedescribed conventional coking operation carried out in byproduct coking ovens.

It is another object of this invention to produce coke of substantially uniform size and strength and all of which is suitable for metallurgical purposes, as contrasted with coke nonnally produced in a byproduct coke oven which is characterized by an appreciable amount of undersize material.

It is an additional object of this invention to produce coke which possesses porosity and density characteristics which are closely controlled, and which can also be very low in ash content. Such cokes are well suited for use in the phosphorus and calcium carbide industries as a reductant, and as a carbonaceous aggregate in the production of Soderberg anodes or prebaked anodes for the aluminum industry.

It is yet another object of this invention to produce coke in a period of time which is substantially shorter than the times employed to produce coke by conventional byproduct coking oven techniques, which typically require about 18-24 hours.

It is still another object of this invention to produce coke by a process which is substantially continuous in nature and which typically requires less manpower and maintenance costs than are required by the byproduct oven coking technique, which may be referred to as a "multiple batch" process.

The process, in a preferred embodiment, comprises producing metallurgical coke from two main active particulate carbonaceous ingredients, viz coal and a raw uncalcined coke made by coking a heavy liquefiable hydrocarbon to a volatile matter content exclusive of water of about 8 percent to about 20 percent e.g. raw petroleum coke, and a plasticizing agent for one or both of these materials. Minor amounts (up to about percent by weight, of the total particulate blend) of inert (essentially nonfusible during the coking process) materials such as anthracite, or coke breeze, or calcined petroleum coke, or poorly fusing or oxidized raw petroleum coke, or ores to be reduced in subsequent use of the coke may also be included in the fonnulation. In less preferred embodiments. the final coke may sometimes also be prepared from raw uncalcined coke as the sole active particulate starting material plus a plasticizing agent for same; or from raw or partially devolatilized bituminous coal as the sole active particulute starting material plus a plasticizing agent for it. Generally and preferably. however, the invention will be carried out using as the active particulate starting material a blend of coal and raw uncalcined coke, 100 parts of blend in proportions of to 15 parts of the raw uncalcined coke and 15 to 85 parts of the coal. A very important part of the process is the use of plasticizing agent(s), which agent(s), serve many functions, but primarily to soften the particulate starting materials and to lower the temperature(s) at which the main active particulate ingredient(s) may be press-formed or briquetted to produce formed green bodies having strengths satisfactory for further processing and subsequent ultimate use after being carbonized.

The starting raw uncalcined coke is preferably of the delayed coker" type made by coking a heavy, liquefiable petroleum hydrocarbon to a volatile matter (VM) content exclusive of water of from about 8 percent to about 20 percent, and more typically from about 1 1 percent to about 16 percent; it is preferred, also, that it be able to fonn a button," as this property is defined hereinafter in connection with the volatile matter content test, and that it have a VM content of at least about 10 percent, particularly if the raw uncalcined coke is employed as the only active particulate starting material. lts VM content may be as low as 8 percent when used in admixture with coal.

The coal has a volatile matter content of from about 15 percent to about 45 percent and may cover the low, medium and high-volatile coal range; if the coal has a VM content exceeding about 20 percent and is used as the sole or major active particulate starting material, it is necessary to subject the starting coal to an initial or preliminary partial devolatilization step before it is used in the process and this is discussed in more detail hereinafter.

Other objects, and coincident advantages, and a complete understanding of the invention will be apparent to those skilled in the art after a study of the drawings, and a reading of the specifications and claims.

BRIEF DESCRIPTION OF THE DRAWINGS It has been found that the foregoing objects and advantages are achievable by carrying out the processes set forth in the schematic drawing of FIG. 1, or in block or outline fonn in the accompanying drawings of FIGS. 2 and 3.

DETAILED DESCRIPTION OF THE DRAWINGS AND OF THE PREFERRED EMBODIMENTS As illustrated in FIG. 1, the starting particulate material(s) typically are stored in separate hoppers l, 2 and 3 and blended in a desired proportion by means of controlled feeders. The materials in these hoppers may be dewatered or partially dried if necessary. If not sufficiently dry, the starting material(s) or mixture is fed to a rotary dryer 4 prior to entering a pulverizer system. In the pulverizer or mill 5 the starting material(s) or mixture is crushed, milled or ground (additionally mixed) to a typical particle size of substantially percent minus ls-inch if the particles are not already this size; however, they may be coarser or finer than this. A screen 6 may be used to restrict or control the size of the particles used in the subsequent steps of the process. However, particle sizing exceedingly fine, for example 100 percent minus 325 mesh, (or even as fme as 50 percent minus 200 mesh) is generally avoided because unnecessary for optimum results and unduly expensive; that is, it accomplishes nothing extra, adds to the processing costs, and can result in formed bodies which are undesirably dusty.

A conditioning temperature above about 300 F. and typically between about 320 F. and about 500 F., more typically between about 340 and about 450 F., but below that at which the particles readily fuse or agglomerate is generally employed prior to addition of the plasticizer. As illustrated in FIG. 1, the main or major portion of the heating of the particles to the desired temperature may be carried out by entrainment heating in an inert gas stream such as in conveying pipe 8, after the particles pass through surge bin 7, and weight feeder 7a and seal valve 7b. The heat for the entrainment heating system is provided by the combustion of gas in chamber 9 of the air-gas mixture from mixer 10. The heated particles are then separated from the hot gases in cyclone-collector or cyclone-separator it. As much time as is convenient (rapidly or slowly, as desired, or as best suited to process rates or the equipment available) may be taken to reach the desired elevated conditioning but nonfusing temperature. The particles may also be heated in the mill 5, either entirely or partially or in many other ways provided an inert atmosphere or an inert gas system is maintained to prevent excessive oxidation, which is generally detrimental to fusibility of the particles and strength of the finished product.

Cyclone-wparator 111 will typically have a high-separation efliciency such as in excess of about 95 percent. The separated solids are then conveyed to mixer 17, where they are then mixed with the plasticizer, while the flue gases and residually entrained fines from the cyclone-separator 11 are directed elsewhere. They may be cycled back into the process such as through a second cyclone-separator 12, which typically will be about 50 percent efflcient in separating the residual fines from the flue gases. Part of the residual fines, then, from separator 12 are cycled to mixer 17 while part also are cycled back to combustion chamber 9 together with return flue gases. A portion of the gases from cyclone-separator 12 are recycled to combustion chamber 9 to provide temperature control of the heating gases while excess gas from 12 is vented to the atmosphere. Any fines in the exhaust gases vented to the atmosphere may be disposed of by combustion or recovered, after cooling, in a baghouse.

The heated particles from cyclone-separator 11 and some also from separator 12 are, as aforesaid, typically conveyed to a continuous mixer 17, such as a pug mill or continuous mix muller. It should be apparent from FIG. 1 that the particles entering mixer 17 are in a heated condition. The particles are mixed in mixer I7 with a heated plasticizer from plasticizer tank 13, the temperature of the plasticizer in the tank being sufficiently high to substantially lower its viscosity but not so high as to boil or decompose it. This tank and/or the plasticizer within same may be heated, such as by means'of electric heater 14, or by other suitable means such as hot oil or steam. A metering pump 15 may be used to control the amount or proportion of plasticizer (typically from about I to about 8 percent and more preferably from about 2 to about 6 percent by weight of the particulate materials entering mixer 17 which is fed to mixer 17 to be mixed with the heated particles. This proportion of plasticizer may also be expressed as parts per hundred (p.p.h.) parts of particulate materials. Auxiliary heating means 16 typically are used in the plasticizer feed lines to the mixer to rapidly raise its temperature to the approximate level of the particles. The heated plasticizer may conveniently be sprayed onto the particles in mixer 17. Mixer l7 typically will also be heated, such as by the burning of natural gas in air in chamber 18 and passing the heated gas to heater jacket 19, so as to keep the particles-plasticizer mix at the desired elevated temperature for molding or briquetting. This elevated temperature" is at least as high as about 300 F. but is also below the fusion temperature of the base solid carbonaceous material(s) before these material(s) are mixed with the plasticizer. The plasticizer and particles are typically rapidly mixed in a short period of time, such as in from about 0.5 to about l minutes while they are still at an elevated temperature above about 300 F. during which time the mix fuses or becomes plasticlike. The mix is then molded or briquetted, such as by a briquet press 20, before it is rendered nonplastic due to overheating (either timewise or temperature wise). The retention time that the mixture of particles and plasticizer is maintained at maximum temperature prior to pressing is generally limited to no more than about minutes. (Typically the material flows continuously through the mixer and a proportion of the total retention time is required to complete mechanical mixing; the remainder is necessary to allow for interaction or alloying between the plasticizer and raw coke and/or raw coal, which interaction takes place in mixer 17 and also in hopper-feeder 20a both of which are maintained under substantially inert or nonoxidizing conditions.)

In the forming or briquetting step, the pressure employed is variable depending on the temperature of the particles being formed, the formulation being processed, the type of press or forming operation used, etc.

The formed green bodies produced typically have an apparent density (A.D.) between about 0.85 and about 1.25 grams per cubic centimeter (g./cc.) and a porosity between about 8 percent and about 37 percent. After pressing. the hot formed green bodies are transferred, such as by conveyor 21 (which typically will also be housed in a substantially inert or nonoxidizing atmosphere) to a carbonizer 22 where they are gradually but rapidly heated (preferably 8 hours or less) in a substantially inert atmosphere to the degree (e.g. typically l,000 F. to 2,000 F.) that their volatile matter content is substantially reduced from the green state.

The foregoing described technique for carrying out the process is that which is preferred, and is also that which is illustrated in the block drawing of FIG. 2. It should be apparent, however, that there are process techniques or variations which are somewhat different from the foregoing procedure but which are also within the scope of the invention. The block drawing of FIG. 3 illustrates such an alternative technique. In this illustrated process the starting particulate materials are first mixed with the plasticizer before being heated, rather than being separately heated before being mixed with the plasticizer. The entire mixture is then relatively rapidly heated during which heating step the plasticizer alloys with the particulate starting materials. This heating step can conveniently be carried out while simultaneously mixing all of the materials and also while conveying the materials to the fonning apparatus. In the heating step the mixture is heated to a temperature at least as high as about 300 F. but below the fusion temperature of the particles of the base coal and/or coke materials, and the plasticized mixture, which has become fused or plasticlike, is briquetted or pressed while it is still above about 300 F. and before it is rendered nonplastic. The retention time that the mixture of particles and plasticizer is maintained at maximum temperature prior to pressing is generally limited to no more than 5 minutes. It will be noted that in this process variation the retention time at maximum temperature is sub stantially the same as in the process variation of FIG. 2. It will be appreciated, however, that, because no elevated temperature conditioning step(s) are carried out, more time is generally required or employed in the heating step to get the plasticized mixture up to maximum temperature than in the heating step of the plasticized mixture of FIG. 2. The briquetting and carbonizing steps are then carried out in the same manner as for the process of FIG. 2. It is important that the temperature of the plasticized particles reach at least about 300 F. for any of the blends of this invention. Otherwise a poor briquetting operation follows and the strength of the carbonized briquettes is poor. The maximum temperature(s) and retention time(s) at maximum temperature which may be employed will vary and must be adjusted for each type of formulation to be briquetted; but for any given formulation there must be close control of the time and temperature conditions. Otherwise the mixture employed will not be softened enough for satisfactory briquetting or will be overheated or heated too long and rendered nonplastic and unsatisfactory for briquetting.

It should also be pointed out that the main function of the plasticizers described herein is as such rather than as bindeis. In other words, they are used mainly as processing aids in enabling the use of lower-pressures and temperatures in forming than would otherwise be necessary to produce strong green bodies. That they function as such is apparent from the fact that the plasticizer plus an inert such as anthracite, when heated to forming temperature, and pressed, does not yield a cohesive briquet; the active particulate material(s) alone when processed in this same manner, e.g. heated and pressfonned, also do not become cohesive or yield a cohesive body. But the active particulate material(s) plus plasticizer when heated and processed in an identical manner do form cohesive bodies. Consequently, neither the plasticizer nor the active particulate material(s) can be acting solely as binder during the fonning step. Therefore, the plasticizers act as such, viz as plasticizers before the forming operation, rather than as a binder. This is not to say, however, that the plasticizers cannot be converted partially or largely to carbon (and thus function also as a binder) during the carbonization step.

Other process variations which are possible and which should be obvious are to heat the particulate starting material(s) (either the active and/or the inert) separately from the plasticizer by techniques other than entrainment heating, such as by batch techniques or in a mill or in a mixer or in a fluidized bed, etc.; and then mix the plasticizer with the heated particles. The particulate starting materials may also initially be heated separately and to different temperatures before they are blended with each other and with the plasticizer. If so, the inert material may typically be heated to a higher temperature than the active material. The plasticizer may be separately heated or may receive part or all of its heat from the preheated particles. Other possible process variations will be obvious to those skilled in the art.

In order that the invention may be completely understood the following examples are set forth:

EXAMPLE 1 Fifty parts of bituminous coal having a VM content of 26.1 percent and 50 parts of raw petroleum coke having a VM content of 13.5 percent stored in separate hoppers l and 2 as illustrated in FIG. 1 were blended in these proportions by means of controlled feeders. The blended materials contained about 5 percent moisture and were dried in rotary dryer 4 by subjecting them to a temperature of about 250 F. for about I minutes. The dried mixture was then fed to a pulverizer system such as used in powdered coal burners. In the pulverizer or mill 5 the mixture was milled or ground (and additionally mixed) to a particle size such that substantially 100 percent of the mixture could pass through a mesh screen (Tyler) (or roughly minus zit-inch). A screen 6 was used to restrict or prevent larger sized particles from entering the subsequent steps of the process.

The main or major portion of the heating of the particles to the desired temperature was carried out by entrainment heating in an inert gas stream in conveying pipe 8, after the dried, milled and mixed particles passed through surge bin 7, weight feeder 7a and seal valve 7b. Weight feeder 7a was used to closely control the quantity of material entering the conveying pipe 8. In the present example, feeder 7a was set to admit 4,640 pounds (:3 percent) of particulate material per hour to conveying pipe 8. (Although illustrated as horizontal in FIG. I, it should be understood that conveying pipe 8 may be at any desired slope including vertical, with the particles moving in a downward direction.) Conveying pipe 8 was 2 feet in diameter and 2l feet long. The heat for the entrainment heating system was provided by the burning of natural gas in combustion chamber 9 of the air-gas mixture from mixer 10. The combustion chamber 9 was designed to provide 2.54 million B.t.u./hour heat release; 1.73 million Btu/hour of this being provided by the burning of 29 s.c.f.m. (standard cubic feet per minute) of natural gas in 290 s.c.f.m. of air from the air-gas mixer 10; and 0.81 million B.t.u./hour of this being provided by the return and/or combustion of hot flue gases and fines from the "Fines" cyclone-separator 12. The nonoxidizing gas leaving combustion chamber 9 has an output temperature of 800 F. and a rate of 7,950 cubic feet per minute (c.f.m. This rate of flow corresponds to a linear velocity of the gases in the pipe 8 of about 50 feet per second. The particles are conveyed in this gas stream and have an average retention time in the pipe of less than a second while they are heated to such a temperature that after separation from the gases in the cycloneseparator ll they have a temperature of about 400 F. (As previously indicated. although rapid heating rates are preferred for maxlmum production, as much time as is convenient, rapidly or slowly, as desired, or as best suited to process rates or the equipment available, may be taken to heat the particulate starting materials to the desired elevated, nonfusing temperature before they are mixed with the plasticizer. Also as previously indicated, entrainment type heating is not essential and the particles may be heated in the mill 5, either entirely or partially or in many other ways, such as in a fluid bed.)

The typical cyclone-separator 11 used is so designed as to have a high-separation efliciency, such as in excess of about percent, or about 97 percent, for the size particles being processed. The separated solids are then passed to mixer 17, (97 percent of 4,640 or about 4,500 pounds/hour) where they are then mixed with the plasticizer, while the flue gases and residually entrained fines (about I40 pounds/hour) from the cyclone-separator 11 are directed elsewhere. In the process illustrated in FIG. 1 and the present example, they are utilized to a great extent by being cycled at a flow rate of about 5,6 I0 c.f.m. back into the process such as through a second cycloneseparator 12, which typically will be about 50 percent efficient in separating the residual lines from the flue gases. About half of the residual fines, then, (about 70 pounds/hour) from separator 12 are cycled to mixer 17; while part also (about 58 pounds/hour) are cycled back to combustion chamber 9 together with return flue gases. Another minor part (about 12 pounds/hour) are disposed of by combustion or recovered, after cooling, in a baghouse. A damper 12b is typically used to restrict the proportion of fines which are so processed and to favorably proportion the percentage cycled back to combustion chamber 9. Seal valves 1 1a and 12a from cyclones II and 12 permit the flow of solids and eliminate gas flow into the mixer, the feed rate into the mixer being effectively controlled by weight feeder 7a.

The heated particles from cyclone-separator 11 and a minor proportion also from cyclone-separator 12 are, as aforesaid, conveyed to a mixer 17. The heated particles were mixed in mixer 17 with a heated plasticizer from plasticizer tank 13. the temperature of the plasticizer in the tank being sufiiciently high to substantially lower its viscosity but not so high as to boil or decompose it. This tank and/or the plasticizer within same was heated by means of heater 14. In the present example, the plasticizer used was thermal tar having the following properties:

Specific Gravity at 20/20 C.l.02

The viscosity of the thermal tar in Saybolt Universal Seconds at 210 F. was 95.

A metering pump 15 was used to control the amount or proportion of plasticizer cycled into mixer 17 to be mixed with the heated particles. Preferably, as aforesaid, this will vary from 2 to about 6 parts by weight per hundred parts of the particulate materiaKs) entering mixer 17 or will be from about I I to about 33 gallons per hour. In the present example 5 parts or percent thermal tar by weight was used. Auxiliary heating means 16 were used in the plasticizer feed lines to the mixer in order to rapidly raise the temperature of the plasticizer from 300 F. to the approximate level (400 F.) of the particles and also the temperature desired for briquetting. These auxiliary heating means are used because it is preferred not to heat the plasticizer to this temperature level for too long a period of time prior to mixing it with the heated particles. The heated plasticizer of lowered viscosity may conveniently be sprayed onto the particles in mixer 17. Mixer 17 is typically also heated by hot gases, such as from the burning of natural gas in chamber 18 (e.g. 0.8 s.c.f.m. of natural gas in 8.8 s.c.f.m. ofair to provide 51,170 B.t.u./hour), in heater jacket 19, so as to keep the particles-plasticizer mix at the desired elevated temperature for pressure-forming or briquetting; the products of combustion from the heater jacket being vented to stack. The plasticizer and particles were then rapidly mixed in mixer 17, which typically has a maximum retension time of about minutes and more typically about 10 minutes, and were then pressure formed in double roll briquet press at a pressure of 28,000 p.s.i., while at about the 400 F. temperature and before the alloy formed was rendered nonplastic, after which the hot formed green bodies (about 4,500 pounds/hour were passed, by conveyor 21, to a carbonizer 22 where they were gradually heated in 6 hours in an inert atmosphere to a maximum temperature of 1,800 F.

The briquets produced were pillow shaped and were 3 inches long, 2 inches wide and possessed a maximum thickness of 1% inches; it should, however, be appreciated that the green bodies of this invention can have other shapes such as semlcylindrical, or tubular, or doughnut-shaped, etc; depending in large part upon the necessity or desirability of producing porosity in the packed bed of the furnace in which they are used. Such alternative shapes may also readily be resorted to in order to facilitate rapid evolution of volatiles in the carbonizing step (and hence a rapid carbonizlng step) and, at the same time, the minimization of flaws, or cracks or spalling, etc, during the carbonization step. Generally, however, the formed green bodies of the invention will be so shaped that at least one of its dimensions does not exceed about 2 inches.

it will be noted that in the foregoing example 50 parts of raw petroleum coke, 50 parts of coal, and 5 parts of plasticizer, by weight, were used. Most typically and preferably in the present invention the active material(s) used will be a blend of coal and raw coke and this blend will comprise from 15 to 85 percent of a coking coal, and correspondingly from 85 to 15 percent of raw coke (preferably raw petroleum coke). As indicated in FIGS. 2 and 3, to these active base materials may be added minor amounts ofinert.

The examples in the following table illustrate the effect of some of the processing variables of the present invention on the properties of the resultant carbonized bodies. The coal and the raw petroleum coke and the roll pressure employed were the same as used in example 1. Different plasticizers were used, in varying amounts, as indicated in the table. A carbonizing time of 6 hours was employed in each of the examples, using an even upheat rate to a final temperature of l,762 F. in this period.

in the foregoing examples, as well as in example 1, regular size coal and coke materials were used. Regular" material is typified by the following screen analysis:

Mesh Size Coal Petroleum Coke in. 10 m. 1.04 0.42

Coal Tar Properties 900 ccntipoises Specific Gravity, 25/25 C. Benzene Insoluble, Wgt. Viscosity, 25 C. Distillation (D-20) Up to 517 F. 2.65% 517 F.-680 F. 13.60% Residue, or above 680 F. 83.75%

Additional tests were carried out employing processing conditions similar to those set forth in table 1 but wherein the raw petroleum coke was replaced with calcined petroleum coke; or wherein the plasticizer was omitted; or wherein the coal as used was a high volatile coal and was percent or more of the blend (it was not initially partially devolatilized before being used). In all instances unsatisfactory results were obtained.

As previously pointed out, the invention may be carried out by using the raw uncalcined coke as the sole active particulate starting material, said coke, when used alone, having a volatile TABLE I Modified Weight percent Plastinizer p.p.h. Mix, tumbler test,

(parts per iundred temp, wgt. percent Apparent Example Coal Coke 01 coal and coke) F. +1" density .2 50 310 72. 1 1. 12 3 50 345 73. 1] 1. 14 4 50 348 79. 2 1. 12 5 50 352 72. 9 1. 15 6 50 402 86. 8 1. 20 7 50 442 62. 2 1. 19 8 50 354 63. 2 1. 10 E) 26 340 80. 8 1. 33 10 25 356 81. 6 1. 28 11 25 360 71. 7 1. 26 12 25 350 82. 3 1. 39 13 25 352 84. 2 1. 33 14 0 437 60. 2 1. 40 15 0 370 56, 2 1. 42 16 0 434 56. 7 1. 44 17 0 399 52. 6 1. 43 18 1 380 61. 3 1. 13 19 1 75 354 64. 7 1. 16 20 1 75 376 60.1 1.11 21 1 75 408 66. 5 1. 12 22 l 100 340 59. 6 1. Q9 23 1 100 374 55. 4 1. 06 24 l 100 384 53. 2 1.01 25 7 100 0 5.0, coal tar 512 57. 8 0.

1 Bituminous coal devolatilized to approximately 20% volatile matter content. 2 Mixture of bit misqs qsl s q e ilirs i 5 .1 .lqzzes ks qlisa.

matter content of at least about percent and ranging up to about percent, and preferably about 1 1-16 percent, exclusive of water. The raw coke referred to may be obtained as a fusible residue by the thermal cracking or coking of petroleum hydrocarbon oils, cracked asphalts, straight run asphalts, coal tar pitch, wood tar pitch, and the like. (As previously indicated, however, an especially useful and preferred raw coke is raw petroleum coke produced in a delayed coker.) Also, as previously pointed out, the invention may be carried out by using raw coal or partially devolatilized coal as the sole active particulate starting material, so long as its VM content does not exceed about 20 percent. The use of raw coke alone or of coal alone (having a proper VM content) are illustrated in the examples of table I. As is apparent from the tumbler tests, however, mixtures of coal and raw coke result in higher values and are, therefore, preferred in the processes of the present invention.

Only those raw cokes which have a volatile matter content within the range of about 8 to about 20 percent, 10 to 20 percent if used as sole active particulate material) or which in a separate step are devolatilized so that the volatile contents are in this range, and, more preferably, in the range of about I 1 percent to about [6 percent, can be employed in the processes of the present invention. With cokes having volatile matter contents in excess of about 20 percent (water not being included in this figure) difficulty is generally encountered in the carbonization step due to excessive fusibility. Raw cokes having volatile contents of about 10 percent or less (when used without any coal) present difficulty in that they fail to alloy or interact with the plasticizing agent. Raw cokes low in sulfur are also preferred.

When the raw coke as obtained has a volatile matter content above about 20 percent it can be heated under controlled conditions, which should avoid localized overheating, to reduce the volatile matter content to come within the ranges specified. This can be done at relatively low-temperatures of about 500-l,000 F. Care should be taken that oxidation does not occur and that the volatile matter content is not reduced to a point below that of the ranges set forth.

The plasticizer should be neither substantially vaporizable (at atmospheric pressure) nor substantially thermally decomposable below about 490 F., which temperature is well above the temperature at which the alloying effect of the plasticizer with the raw coke and/or coal generally occurs. Suitable substances for plasticizers include coal tar, coal tar fractions, coal tar pitches, certain high-boiling hydrocarbon oils and residues produced in catalytic cracking of petroleum distillates such as thermal tar, petroleum pitch, wood tar pitch, anthracene oil, heavy wood tar oils and pitches, heavy lignite tar oils and pitches, phenanthrene, and the like. Heavy petroleum hydrocarbon residues and asphalts, whether cracked or straight run, may also be used as plasticizers.

The selection of a plasticizing agent (which may also be referred to as a plasticizer or alloying agent) depends upon a number of factors such as the material(s) with which it is alloyed, its cost, etc. Any plasticizer which will partially alloy with the raw coke and/or coal used can be used. Not all are exactly equivalent. Aromatic hydrocarbons are preferred. The oxygen or nitrogen derivatives of aromatic hydrocarbons are also useful, but are less desirable than the hydrocarbons. The plasticizer should not contain substantial amounts of substances which decompose to give strongly oxidizing decomposition products. Cycloparaffinic hydrocarbons or their derivatives may be used, for example, the furfural extract of heavy lubricating oils. Mixtures of the hydrocarbons and their derivatives may be used to advantage in many instances.

Preferably, as previously pointed out, the plasticizer should not vaporize or decompose substantially below about 490 F. Of course, in the carbonizing operation a certain amount of volatile hydrocarbons and other byproducts resulting from the pyrolysis of the plasticizer are obtained, but the most desirable plasticizers are those which are converted to a large extent into coke. Excessive production of vapors and gases tend to unduly increase the porosity of the coke bodies. However, in view of the small proportion of plasticizer used which is never greater than about 8 percent, and in view of the fact that some porosity in the bodies produced is desirable, this is not generally a problem. High-sulfur content materials are generally undesirable because metallurgical coke having a high-sulfur content is frequently objectionable to the user of the coke.

The comminuted coal and/or raw coke and the plasticizer can be preliminarily mixed at room temperature where this is convenient, particularly if the plasticizer is in finely divided solid condition. Likewise those plasticizers which are normally liquid can be mixed cold with the coal and/or coke. Or the mixing can be carried out at elevated temperatures such as by heating the coal or coke, or a fairly uniform mixture of coal and/or raw coke and plasticizer, to a temperature above about 300 F. and typically in the range of about 320500 F. and more typically 340-450 F and the mixing step carried out in any suitable type of equipment, so that mixing and plasticizing or alloying take place simultaneously. The proper time-temperature for this alloying treatment is quite critical and will vary depending upon the volatile matter content of the coal and/or raw coke and the particular plasticizer employed and its viscosity. in any case, the plasticized particles should not be heated for too long a period of time and/or to too high a temperature before they are pressure-formed since it is possible that such treatment will render the plasticized particles nonplastic and result in difficulties in fonning the green bodies, or in green bodies of poor strength. These time-temperature conditions, or holding times at maximum temperature can readily be established for any given mixture described herein and using the guidelines discussed herein, using the briquettability of the plasticized particles and the properties of the baked briquets as criteria. The alloying treatment should preferably be carried out in a nonoxidizing atmosphere, particularly when or after the plasticized particles approach or reach their maximum temperature.

In certain instances, the mixing can be carried out with the raw materials warmed, e.g. to l0O-200 F., but at a temperature below that at which the alloying effect is initiated or complete and this followed by further processing at a higher temperature.

As stated care must be taken that the alloying treatment is controlled so that it does not proceed too far. This usually can be controlled by the temperature used, although time has a substantial effect. If a mixture of a plasticizer and coal and/or raw coke is heated while mixing at a temperature above the range given, or above the maximum desirable temperature for that particular mixture, it goes through first a pasty form and then the mixture changes in character and becomes too dry to extrude and difficult to mold such as by a continuous roll briquetting operation. In other words, the plasticized coal and/or raw coke should furnish its own lubrication effect on the dies. With certain plasticizers, this over treatment may occur in the temperature range given if the time is extended too long, for example, beyond 5 minutes or even less. As previously indicated, the criticality of the time and temperature relationship in the alloying step varies with the amount and kind of plasticizer employed. It also varies, with the volatile matter content and particle size of the coal and/or raw coke. In general, however, the small or line coal and/or raw coke particles which are typically employed in the present invention alloy rapidly because of the large surface area and small diameter of the particles.

If the alloyed mixture has gone to a point beyond that readily extrudable or moldable, the mixture not only becomes difficult to roll briquet or extrude, but also results in the formation of bodies which may develop imperfections and be of Petroleum coke Parts I percent raw petroleum coke with a VM of 15 percent, or 18 percent or if the particulate material were 50 percent coal, etc. Also, as previously indicated, if raw petroleum coke of 8 or 9 percent VM content is employed, it will not be used alone but will typically be used in conjunction with substantial amounts of coal. it is apparent also that the time and temperature conditions may vary for such coke formulations as the following, all of which are embraced within the invention and within the drawings depicting same:

Bituminous coal llasticizer (parts per hundred parts of coke and coal) VM VM (percent) Parts (percent) Asphalt. Anthracene oil. Thermal tar. Petroleum pitch. Thermal tar.

Thermal tar. Coal tar pitch. Coal tar. Thermal tar. Coal tar.

Coal tar pitch. Thermal tar. Coal tar. Thermal tar.

1 In the foregoing formulations h, k. l, m, n, o and p, the bituminous coal was partially devolatillzed prior to blending (in order that the VM content of the coal-petroleum coke mixtures would not exceed about 20%) before it was blended with the petroleum coke and processed in accordance with the steps of this invention. In all cases in the alloying heating step, the particles will be heated long enough (within the time ranges previously set forth) and/or to a sufliciently high temperature (also within the previously discussed temperature ranges) to bring about the desired softening and alloying efiect, but not so long and/or to such high temperatures that the alloy formed is rendered non-plastic. a V

Plasticized coals or raw cokes that may be employed in this process must, after being pressure-formed or briquetted, be of a character in which there is little plastic and no liquid flow during any stage of the carbonizing operation. If the coals or coke have too high a volatile matter content or if the plasticized mixtures tend to melt and flow before decomposition of the decomposable components of the formed green bodies has occurred, the minute channels from the interior of the bodies to the exterior by which the decomposition vapors escape will tend to seal off, resulting in processing problems in the carbonizing step and the production of large pores and carbonized bodies of poor strength. However, when prepared with the materials having the properties previously described and according to the methods outlined, such flow does not occur and the vapor escape channels remain small and uniformly dispersed throughout the bodies being carbonized, so that the gases can escape rapidly and without the production of large pores or channels.

As previously indicated, if it is desired to use a coal having a volatile matter content of from about 20 percent upwards to about 45 percent in the present process, in an amount such that the resultant blend (coal plus raw petroleum coke) would have a volatile matter content higher than about 20 percent by weight, then it is necessary to partially devolatilize such coals by any suitable means known to those skilled in the art, so that the volatile matter content of the resultant blend is no higher than about 20 percent. If this partial devolatilization of the coal operation results in excessive agglomeration of the coal, it may be preliminarily crushed to reduce it to a reasonable size, after which it can then be used as a raw material in the present process.

All of the materials in the blend to be briquetted or pressure formed are generally heated to approximately the same temperature, In the process of doing this, however, the various ingredient(s) will be affected differently. For example, if a substantially inert material such as anthracite is used, it will typically merely be heated up to operating temperatures; on the other hand the coal and/or raw petroleum coke blended with the plasticizer undergo an alloying effect. The time and/or temperature the particles are kept in or heated to in this heating step also depend upon a number of factors in addition to those already discussed. For example, if the particulate material being heated is l00 percent raw petroleum coke (viz no coal or inert) having a volatile matter (VM) content of about l2 percent, the conditions are different than if it were The forming apparatus 20 or rolls of the briquetting machine may be at any desired temperature, such as at approximately the same temperature as the particles or higher, or at room temperature, or at a temperature intermediate of these, etc. The briquetting rolls may be water cooled, or oil cooled, etc. The heated solids prior to briquetting must be protected from undue atmospheric oxidation which is detrimental to the strength of the finished product. it is also apparent that in the presence of excess air there is danger of ignition and combustion. An inert gas atmosphere may be provided.

As previously indicated, the pressure employed in the forming step is variable depending on the temperature of the plasticized particles being fonned, the formulation being processed, the type of press or forming operation used, etc. [in a piston press it will be between about 500 and about 15,000 p.s.i., employing lower pressures with higher temperatures and vice versa. in a roll press, the pressure (P) will typically be between about 4,000 and about 90.000 p.s.i., where P =F/A (A total area of pockets under pressure along the line of contact between the rolls; F Force applied to the rolls of the press).] For example, blend temperatures of 300-350 F. and pressures of 1,000 to 2,000 p.s.i. in a piston press may result in poor green and/or baked body strengths, whereas temperatures of 350-450 F. and pressures of 500 p.s.i. can result in bodies of good strength. Typically, no more pressure should be employed than will produce a formed green body having a porosity of at least 8 percent, while on the other hand, at least as much pressure should be employed so as to produce a green body having a porosity no greater than 37 percent In other words, if the porosity of the formed green body is under 8 percent or is higher than 37 percent, or is not a satisfactory level, whatever is desired, then the pressure employed may be reduced or increased accordingly until the porosity of the resultant green bodies is at the desired level. Green body porosities between about 15 percent and about 30 percent are more typical and preferred.

A roll-press is most preferred for volume production and when such a forming apparatus is employed the "pressing time" (the time when the alloyed particles being shaped are actually under pressure or when pressure is actually applied) is usually less than 2 seconds and typically less than one. Other fonning apparatus can be employed, such as previously discussed.

in piston presses, pressures less than 2,500 p.s.i. are most typical and, generally, pressures higher than this are wasteful of energy. With many of the carbonaceous blends or compositions of the present invention, particularly those having a relatively high VM content, when pressures above about 3,500 p.s.i. are employed, an increasing percentage of the briquets or formed articles have flaws (particularly after they are carbonized). Pressures above about 4,000 p.s.i. when using a piston press are generally avoided, therefore, unless significant amounts of inerts have been added to the mixture to be processed, or unless the composition or mixture to be processed has a low-VM content in which cases the use of such higher pressures may be advantageous. Higher pressures are used in roll presses.

A minimum porosity of at least 8 percent should be maintained in the formed green body in order that a minimum of problems arising in the forming and carbonizing steps and in order that the carbonizing step may be carried out in a rapid operation. if the porosity of the formed bodies is too low and attempts are made to rapidly carbonize such bodies, then the escaping remaining volatiles tend to rupture the articles and produce coke of unsuitable size or strength for metallurgical purposes.

Changing the temperature to which the alloyed particles are heated, or making changes in the formulation which is employed to make the green bodies also, of course, affect the porosity of the bodies produced. As aforesaid, the maximum porosity of the formed green bodies is 37 percent. lf higher than this, then they are too weak or have too low an apparent density (after being carbonized) for their contemplated uses. The apparent density of the carbonized product is generally between about 1.0 and 1.5 g./cc. With regard to the apparent density of the formed green bodies, this should be between about 0.85 and 1.25 g./cc.; of course the lower density bodies have the higher porosity and the higher density green bodies have the lower porosity.

After the alloyed or plasticized particles are pressurefonned, the formed green bodies preferably are also substantially immediately carbonized, without substantial cooling. This is because if the temperature of the formed material is permitted to drop very much between the forming and carbonizing steps, undesirable cracks or flaws are much more likely to develop in the formed articles than if they are carbonized immediately without any substantial cooling.

in the preferred operation wherein the particles are initially separately heated before being mixed with a heated plasticizer, the overall cycle is such that the operation typically requires no more than about minutes in heating the particles to a temperature between 300 and 500 F., mixing them with the plasticizer, press-forming the alloyed particles while they are still at an elevated temperature between about 300 F. and about 500 F. (viz little or no colling being permitted before the forming operation) and getting the formed articles into the carbonizer. During these phases of the process, no substantial surges are permitted in the cycle. In other words, the carbonaceous particles being heated or the formed carbonaceous masses being processed are kept moving very uniformly or regularly, with no substantial buildup being permitted. However, there may be surges" in any preceding preheating (bringing the particles up to a given relatively low temperature such as about 200 F.) step, which might be employed, or (within limits) in the subsequent carbonizing step, without adverse, or as much adverse, effect upon the quality of the product produced, or the freedom from troubles of the process.

By closely following the process steps heretofore described, the press-formed bodies may be rapidly (e.g. much faster than the 18-24 hours typically required by the prior art byproduct coking oven methods) carbonized, such as to a temperature of between about l,000 and about 2,000 F. (or to a product VM content of 5 percent or less) within a period of 8 hours maximum, without impairment of the qualities of the product. Carbonizing periods of from 3 to 6 hours are typical. Of course a longer period than 8 hours may also be employed, but it will usually be disadvantageous to do so.

The formed green bodies generally do not resoften and stick to each other, or deform upon being processed in the hot carbonizer 22 because of their having been alloyed" and pressure-formed into separate and distinct shapes, during which a strong cohesive bond within the formed green bodies has been effected. Therefore, the bonds between the particles in the individual formed bodies are very good and the carbonized bodies produced are typically of superior strength. With certain formulations and under certain conditions, however, there may be a tendency for the briquets to adhere to each other. if there is a tendency for the briquets to stick to each other during carbonization, they may be subjected to a brief or limited surface oxidation to set and prevent resoftening of their surfaces during carbonization.

The formed green bodies may be carbonizing in any suitable carbonizing apparatus capable of providing a substantially inert or nonoxidizing atmosphere. For best results, however, the carbonizing apparatus 22 is so constructed, or so regulated, that the formed green bodies can be raised to the desired final carbonizing temperature in a well regulated manner. In other words, if the desired final temperature is l,472 F. (800 C.) and the formed green bodies are at a temperature of 400 F. when they leave the forming apparatus 20 and enter the carbonizer 22, they preferably will be heated from the 400 F. (or about 204 C.) temperature to the 800 C. (1,472 F.) temperature at a very closely controlled upheat rate or upheat rates, such as at a rate not exceeding 400 C. per hour up to a temperature between about 500 C. and about 650 C. and then at a rate not exceeding 500 C. per hour up to the final 800 C. temperature. In other words, slower upheat rates are typically employed until the formed green bodies reach a critical temperature or until they are permanently set (typically 600-700 C.) after which somewhat faster upheat rates to the desired end temperatures can be employed. The foregoing type of heating procedure must be employed rather than a heating procedure which would subject the hot formed bodies to a sharp or widespread temperature differential, such as from a temperature of 200 C. immediately to a temperature of 800 C. It is preferable, also, that the temperature of the formed bodies be increased substantially linearly within any given time interval. For example, this means proceeding fairly evenly at an upheat rate not exceeding about 10 C. per minute for any given minute during the initial upheat rate which does not exceed 400 C. for any given hour, and at an upheat rate not exceeding about 13 C. per minute for any given minute during the upheat rate which does not exceed 500 C. per hour, rather than heating the bodies, for example, for 1 hour at 500 C., then transferring them to a zone at 600 C. for another hour, etc.

Controlled temperature gradients which are more gentle than the foregoing such as not exceeding 300 C. for any given hour increment of time, or 8 C. for any given minute increment of time, (for example, a baking rate of 3 C. per minute) are more typical or representative of those generally used in the carbonizing step. The particular upheat rate within the foregoing described ranges which will be chosen and employed will also be dependent upon the density, porosity, size, shape and VM content of the formed green bodies being processed.

Rotary kilns, shaft kilns and moving grates, with gradually increasing temperature zones as the formed bodies proceed through the carbonizer, and capable of providing a substantially inert atmosphere, are very suitable for accomplishing the foregoing type of heating.

After the formed bodies are heated to the desired temperature, they typically are then gradually cooled in an inert atmosphere until they reach a temperature of about 220 F. or lower. A single piece of apparatus, with heating zones and cooling zones, may be employed for both carbonizing and cooling, or cooling may be accomplished in a separate piece of equipment. The cooled formed coke (which may be stored in a product bin or immediately shipped, or immediately used in a cupola or blast furnace, etc.

Generally, carbonizing temperatures at least as high as about l,000 F. are required and temperatures higher than this such as at l,472-l ,760 F. are preferred for optimum properties. Temperatures higher than l,760 F., such as up to about 2,000 E, may also be employed but will generally not be required in order to make a satisfactory commercial product.

The volatile matter (VM) content of the raw cokes and coals of this invention are determined in accordance with the A.S.T.M. Procedure No. D271-48 as modified for peat and lignite, and being exclusive of water. In accordance with this procedure, a relatively small sample of the raw coke or coal is 'heated at 950 C for a period of time between about to minutes. The difference in weight of the sample prior to and after heating constitutes the volatile content" of the material tested. As previously stated, it is preferable that the raw cokes employed in the invention not only have the specified VM content of between about 8 and about 20 percent and more typically between about i l and about 16 percent when used with coal, or of at least about 10 percent when used alone, but that they also form a hard, coke agglomerate or button" while being heated in accordance with the previously mentioned A.S.T.M. procedure, except that a 5 gram sample instead of a 1 gram sample is used. This latter property is essential when the raw coke is employed as the sole active particulate ingredient.

Having thus described the nature of our invention and the uses for the product of our invention, but being illustrated only by the appended claims with respect to the scope of the invention,

We claim:

1. A process for making shaped metallurgical coke bodies which comprises:

A. forming a mixture from (a) a blend of active carbonaceous materials consisting of from to 85 parts by weight of fusible coal particles having a volatile matter content of at least about 15 percent and from 85 to 15 parts by weight of particles of raw, uncalcined coke made by coking a heavy liquefiable, hydrocarbon to a volatile matter content exclusive of water of about 8percent to about percent, the sum of the parts of coal and the parts of raw coke equaling 100; and (b) from about 1 to about 8 parts of a plasticizing agent by weight of the coal and raw coke particles, said plasticizing agent being neither substantially vaporizable nor substantially thermally decomposable below about 490 F., the average volatile matter content of the coal and raw coke particles taken together not exceeding about 20 percent, and said coal and raw coke each being agglomerative when heated and alloyed according to step B following:

B. at least partially alloying said plasticizing agent with said coal and raw coke particles to convert said coal and coke particles to a material which is plasticlike by heating the materials comprising said mixture, which includes the plasticizing agent, for a period of not more than 15 minutes in a substantially inert gas system to a temperature at least as high as about 300 F. and below about 500 F., which is below the agglomerative temperature of the particles of each of the base coal and coke materials before the materials are mixed with the plasticizer;

C. compressing the hot plasticlike mixture in a substantially inert gas system while it is still plastic and above about 300 F., but below the agglomerative temperature of particles of each of the base coal and coke materials, employing a pressure above about 500 p.s.i. to form shaped green bodies which have an AD. of at least 0.85 g./cc. and a porosity no greater than 37 percent; and

D. carbon izing said shaped bodies in a substantially inert gas system with a gradual upheat rate to between about 1,000 F. and 2,000 F.

2. A process according to claim 1 wherein said raw uncalcined coke is delayed coker raw petroleum coke.

.3. A process according to claim 1 wherein an inert material is added to the mixture to be compressed, in amounts up to pans per [00 parts of blend of coal, raw coke and inert and wherein the parts of plasticizing agent employed is based, by weight, upon the parts of blend of coal, raw coke and the inert material.

4. A process according to claim 1 wherein between 2 and 6 parts of plasticizing agent is employed in the mixture to be compressed.

5. A process according to claim 1 wherein said plasticizing agent is thermal tar.

6. A process according to claim 1 wherein the maximum temperature to which the mixture is heated in step B is between about 320 F. and about 500 F. and wherein the time that the mixture is maintained at maximum temperature prior to being compressed in step C is no more than about 5 minutes.

7. A process according to claim 1 wherein the compressing step C is carried out by means of a roll briquetting operation using a pressing time of no more than two seconds.

8. A process according to claim 1 wherein said coal and raw coke particles are heated before being mixed with the plasticizing agent.

9. A process according to claim 8 wherein said plasticizing agent is heated before being mixed with the coal and raw coke particles.

10. A process according to claim 8 wherein said coal and raw coke particles are heated by entrainment heating of the particles in an inert gas stream and wherein the heated particles are separated from the inert gas before being mixed with the plasticizing agent.

11. A process for making shaped metallurgical coke bodies which comprises:

A. forming a mixture comprised of 100 parts of fusible coal particles having a volatile matter content of at least about 15 percent and no higher than about 20 percent, and from about i to about 8 parts of a plasticizing agent by weight of the coal, said plasticizing agent being neither substantially vaporizable nor substantially thermally decomposable below about 490 F., and said coal being agglomerative when heated and alloyed according to step B following;

B. at least partially alloying said plasticizing agent with said coal to convert said coal to a material which is plasticlike by heating the materials comprising said mixture which includes the plasticizing agent, for a period of not more than 15 minutes in a substantially inert gas system to a temperature at least as high as about 300 F. and below about 500 F., which is below the agglomerative temperature of the particles of the base coal before it is mixed with the plasticizer;

C. compressing the hot plasticlike mixture in a substantially inert gas system while it is still plastic and above about 300 F., but below the agglomerative temperature of the particles of the base coal, employing a pressure above about 500 p.s.i. to form shaped green bodies which have an AD. of at least 0.85 g./cc. and a porosity no greater than 37 percent; and

D. carbonizing said shaped bodies in a substantially inert gas system with a gradual upheat rate to between about 1,000 F. and 2,000" F.

12. A process according to claim 11 wherein raw uncalcined coke made by coking a heavy liquefiable hydrocarbon to a volatile matter content exclusive of water of about 8 percent about 20 percent is added to the mixture to be compressed, in amounts up to 15 parts per 100 parts of coal.

13. A process according to claim 11 wherein an inert material is added to the mixture to be compressed, in amounts up to 25 parts per 100 parts of blend of coal and inert and wherein the parts of plasticizing agent employed is based, by weight, upon the 100 parts of blend of coal and the inert material.

14. A process according to claim 1] wherein between 2 and 6 parts of plasticizing agent is employed in the mixture to be compressed.

15. A process according to claim 11 wherein said plasticizing agent is thermal tar.

16. A process according to claim 11 wherein the maximum temperature to which the mixture is heated in step B is between about 320 F. and about 500 F. and wherein the time that the mixture is maintained at maximum temperature prior to being compressed in step C is no more than about minutes.

17. A process according to claim 11 wherein the compressing step C is carried out by means of a roll briquetting operation using a pressing time of no more than 2 seconds.

18. A process according to claim 11 wherein said coal particles are heated before being mixed with the plasticizing agent.

19. A process according to claim 18 wherein said plasticizing agent is heated before being mixed with the coal.

20. A process according to claim 18 wherein said coal particles are heated by entrainment heating of the particles in an inert gas stream and wherein the heated particles are separated from the inert gas before being mixed with the plasticizing agent.

21. A process for making shaped metallurgical coke bodies which comprises:

A. forming a mixture comprised of 100 parts of raw, uncalcined coke particles made by coking a heavy liquefiable, hydrocarbon to a volatile matter content exclusive of water of about percent to about 20 percent, and from about 1 to about 8 parts of a plasticizing agent by weight of the raw coke particles, said plasticizing agent being neither substantially vaporizable nor substantially thermally decomposable below about 490 F., and said coke being agglomerative when heated and alloyed according to step B following;

B. at least partially alloying said plasticizing agent with said raw coke particles to convert said coke particles to a material which is plasticlike by heating the materials com prising said mixture which includes the plasticizing agent, for a period of not more than 15 minutes in a substantially inert gas system to a temperature at least as high as about 300 F. and below about 500 F which is below the agglomerative temperature of the particles of the base coke material before it is mixed with the plasticizer;

C. compressing the hot plasticlike mixture in a substantially inert gas system while it is still plastic and above about 300 F., but below the agglomerative temperature of the particles of the base coke material, employing a pressure above about 500 p.s.i. to fonn shaped green bodies which have an AD. of at least 0.85 g./cc. and a porosity no greater than 37 percent; and

D. carbonizing said shaped bodies in a substantially inert gas system with a gradual upheat rate to between about l,000 F. and 2.000 F.

22. A process according to claim 21 wherein said raw uncalcined coke is delayed coker raw petroleum coke.

23. A process according to claim 21 wherein fusible coke having a volatile matter content of at least about 15 percent is added to the mixture to be compressed, in amounts up to 15 parts per I00 parts of raw uncalcined coke; the average volatile matter content of the raw coke particles and of the coal taken together not exceeding about 20 percent.

24. A process according to claim 21 wherein an inert material is added to the mixture to be compressed, in amounts up to 25 parts per I00 of blend of raw coke and inert and wherein the parts of plasticizing agent employed is based, by weight, upon the parts of blend of raw coke and the inert material.

25. A process according to claim 21 wherein between 2 and 6 parts of plasticizing agent is employed in the mixture to be compressed.

26. A process according to claim 21 wherein said plasticizing agent is thennal tar.

27. A process according to claim 21 wherein the maximum temperature to which the mixture is heated in step B is between about 320 F. and about 500 F. and wherein the time that the mixture is maintained at maximum temperature prior to being compressed in step C is no more than about 5 minutes.

28. A process according to claim 21 wherein the compressing step C is carried out by means of a roll briquetting operation using a pressing time of no more than 2 seconds.

29. A process according to claim 21 wherein said raw coke particles are heated before being mixed with the plasticizing agent.

30. A process according to claim 29 wherein said raw coke particles are heated by entrainment heating of the particles in an inert gas stream and wherein the heated particles are separated from the inert gas before being mixed with the plasticizing agent.

Claims (29)

1. 2. A process according to claim 1 wherein said raw uncalcined coke is delayed coker raw petroleum coke.
2. 3. A process according to claim 1 wherein an inert material is added to the mixture to be compressed, in amounts up to 25 parts per 100 parts of blend of coal, raw coke and inert and wherein the parts of plasticizing agent employed is based, by weight, upon the 100 parts of blend of coal, raw coke and the inert material.
3. 4. A process according to claim 1 wherein between 2 and 6 parts of plasticizing agent is employed in the mixture to be compressed.
4. 5. A process according to claim 1 wherein said plasticizing agent is thermal tar.
5. 6. A process according to claim 1 wherein the maximum temperature to which the mixture is heated in step B is between about 320* F. and about 500* F. and wherein the time that the mixture is maintained at maximum temperature prior to being compressed in step C is no more than about 5 minutes.
6. 7. A process according to claim 1 wherein the compressing step C is carried out by means of a roll briquetting operation using a pressing time of no more than two seconds.
7. 8. A process according to claim 1 wherein said coal and raw coke particles are heated before being mixed with the plasticizing agent.
8. 9. A process according to claim 8 wherein said plasticizing agent is heated before being mixed with the coal and raw coke particles.
9. 10. A process according to claim 8 wherein said coal and raw coke particles are heated by entrainment heating of the particles in an inert gas stream and wherein the heated particles are separated from the inert gas before being mixed with the plasticizing agent.
10. 11. A process for making shaped metallurgical coke bodies which comprises: A. forming a mixture comprised of 100 parts of fusible coal particles having a volatile matter content of at least about 15 percent and no higher than about 20 percent, and from about 1 to about 8 parts of a plasticizing agent by weight of the coal, said plasticizing agent being neither substantially vaporizable nor substantially thermally decomposable below about 490* F., and said coal being agglomerative when heated and alloyed according to step B following; B. at least partially alloying said plasticizing agent with said coal to convert said coal to a material which is plasticlike by heating the materials comprising said mixture which includes the plasticizing agent, for a period of not more than 15 minutes in a substantially inert gas system to a temperature at least as high as about 300* F. and below about 500* F., which is below the agglomerative temperature of the particles of the base coal before it is mixed with the plasticizer; C. compressing the hot plasticlike mixture in a substantially inert gas system while it is still plastic and above about 300* F., but below the agglomerative temperature of the particles of the base coal, employing a pressure above about 500 p.s.i. to form shaped green bodies which have an A.D. of at least 0.85 g./cc. and a porosity no greater than 37 percent; and D. carbonizing said shaped bodies in a substantially inert gas system with a gradual upheat rate to between about 1,000* F. and 2,000* F.
11. 12. A process according to claim 11 wherein raw uncalcined coke made by coking a heavy liquefiable hydrocarbon to a volatile matter content exclusive of water of about 8 percent to about 20 percent is added to the mixture to be compressed, in amounts up to 15 parts per 100 parts of coal.
12. 13. A process according to claim 11 wherein an inert material is added to the mixture to be compressed, in amounts up to 25 parts per 100 parts of blend of coal and inert and wherein the parts of plasticizing agent employed is based, by weight, upon the 100 parts of blend of coal and the inert material.
13. 14. A process according to claim 11 wherein between 2 and 6 parts of plasticizing agent is employed in the mixture to be compressed.
14. 15. A process according to claim 11 wherein said plasticizing agent is thermal tar.
15. 16. A process according to claim 11 wherein the maximum temperature to which the mixture is heated in step B is between about 320* F. and about 500* F. and wherein the time that the mixture is maintained at maximum temperature prior to being compressed in step C is no more than about 5 minutes.
16. 17. A process according to claim 11 wherein the compressing step C is carried out by means of a roll briquetting operation using a pressing time of no more than 2 seconds.
17. 18. A process according to claim 11 wherein said coal particles are heated before being mixed with the plasticizing agent.
18. 19. A process according to claim 18 wherein said plasticizing agent is heated before being mixed with the coal.
19. 20. A process according to claim 18 wherein said coal particles are heated by entrainment heating of the particles in an inert gas stream and wherein the heated particles are separated from the inert gas before being mixed with the plasticizing agent.
20. 21. A process for making shaped metallurgical coke bodies which comprises: A. forming a mixture comprised of 100 parts of raw, uncalcined coke particles made by coking a heavy liqUefiable, hydrocarbon to a volatile matter content exclusive of water of about 10 percent to about 20 percent, and from about 1 to about 8 parts of a plasticizing agent by weight of the raw coke particles, said plasticizing agent being neither substantially vaporizable nor substantially thermally decomposable below about 490* F., and said coke being agglomerative when heated and alloyed according to step B following; B. at least partially alloying said plasticizing agent with said raw coke particles to convert said coke particles to a material which is plasticlike by heating the materials comprising said mixture which includes the plasticizing agent, for a period of not more than 15 minutes in a substantially inert gas system to a temperature at least as high as about 300* F. and below about 500* F., which is below the agglomerative temperature of the particles of the base coke material before it is mixed with the plasticizer; C. compressing the hot plasticlike mixture in a substantially inert gas system while it is still plastic and above about 300* F., but below the agglomerative temperature of the particles of the base coke material, employing a pressure above about 500 p.s.i. to form shaped green bodies which have an A.D. of at least 0.85 g./cc. and a porosity no greater than 37 percent; and D. carbonizing said shaped bodies in a substantially inert gas system with a gradual upheat rate to between about 1,000* F. and 2,000* F.
21. 22. A process according to claim 21 wherein said raw uncalcined coke is delayed coker raw petroleum coke.
22. 23. A process according to claim 21 wherein fusible coal having a volatile matter content of at least about 15 percent is added to the mixture to be compressed, in amounts up to 15 parts per 100 parts of raw uncalcined coke; the average volatile matter content of the raw coke particles and of the coal taken together not exceeding about 20 percent.
23. 24. A process according to claim 21 wherein an inert material is added to the mixture to be compressed, in amounts up to 25 parts per 100 parts of blend of raw coke and inert and wherein the parts of plasticizing agent employed is based, by weight, upon the 100 parts of blend of raw coke and the inert material.
24. 25. A process according to claim 21 wherein between 2 and 6 parts of plasticizing agent is employed in the mixture to be compressed.
25. 26. A process according to claim 21 wherein said plasticizing agent is thermal tar.
26. 27. A process according to claim 21 wherein the maximum temperature to which the mixture is heated in step B is between about 320* F. and about 500* F. and wherein the time that the mixture is maintained at maximum temperature prior to being compressed in step C is no more than about 5 minutes.
27. 28. A process according to claim 21 wherein the compressing step C is carried out by means of a roll briquetting operation using a pressing time of no more than 2 seconds.
28. 29. A process according to claim 21 wherein said raw coke particles are heated before being mixed with the plasticizing agent.
29. 30. A process according to claim 29 wherein said raw coke particles are heated by entrainment heating of the particles in an inert gas stream and wherein the heated particles are separated from the inert gas before being mixed with the plasticizing agent.

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