US3331905A - Method of treating particulate material - Google Patents

Description

L A. HINT METHOD OF TREATING PARTICULATE MATERIAL 7 Sheets-Sheet 1 Filed Jan. 24, 1964 INVENTOR IOHA/VNES ALEXANDROV/CH Hl/VT y 1 1%? l. A. HINT 3,331,905

METHOD OF TREATING PAHTICULATE MATERIAL Filed Jan. 24, 1964 7 Sheets-Sheet :5

INVENTOR IOHA/VNES ALEXA/VDROV/CH H/IVT 18, 1957 1. A. HINT METHOD OF TREATING PARTICULATE MATERIAL 7 Sheets-Sheet 3 Filed Jan. 24, 1964 I .i i C R H Hum -HUW INVENTOR IOHA/V/VE'S ALEM/VDROV/CH H/IVT July 18, 1967 LA. HINT METHOD OF TREATING PARTICULATE MATERIAL 7 Shets-Sheet 4 Filed Jan. 24, 1964 FIG. 4

INVENTOR IOHA/WVES ALBYANDROWCH /-///vr July 18, 1967 l. A. HINT 3,331,905

METHOD OF TREATING PARTICULATE MATERIAL Filed Jan. 24, 1964 7 Sheets-$heet 5 INVENTOR July 18, 1967 A. HINT METHOD OF TREATING PARTICULATE MATERIAL '7 Sheets-Sheet 6 Filed Jan. 24, 1964 INVENTOR IOHAMVES ALEM/VDROV/CH hl/VT July 18, I. A. HINT METHOD OF TREATING PARTICULATE MATERIAL Filed Jan. 24, 1964 7 Sheets-Sheet 7 INVENTOR IOHANA/ES ALEXA/VDROWCH HINT United States Patent 3,331,905 METHOD OF TREATING PARTICULATE MATERIAL Iohannes Alexandrovich Hint, Viirnsi tee 7, Tallin Merivjalka, U.S.S.R. Filed Jan. 24, 1964, Ser. No. 339,912 25 Claims. (Cl. 264-422) This application is a continuation-in-part of my prior filed application Ser. No. 37,022 filed June 20, 1960, now abandoned, and entitled, Method for Preparing Fine Grain Raw Material for the Manufacture of Building Materials.

This invention thus relates to the treatment of particulate materials.

' The invention further relates to the art of comminution and to certain improvements in connection with the processing or treatment of particulate materials by reducing particle size so as to improve certain properties thereof per se or when simultaneously processed and mixed, blended or combined with other materials to improve the resultant mixes, blend or combination.

Still more particularly, the invention relates to comminution of materials that are non-homogeneous, that is, have crystalline parts and amorphous parts in a single particle such as sand grains and certain ores such as taconite, i.e., low grade iron ores. In this regard such particles are split along a line of weakness.

Further, the invention relates to improvements in a process that will result in more effective mixing or blending of different materials in the dry state, each having a particle size less than two inches in a major dimension.

Further, the invention relates to improvements in a process that will result in more effective processing and mixing or blending of different materials in the wet state (water added), provided the grains of the solid materials do not exceed two inches in a major dimension.

Further, and more important, the invention relates to a-process for treating particulate materials of the character mentioned above with reference to the particle size aspects set forth above in which the comminution is by impact in an impact zone with particular reference to an arrangement in which the time interval between two successive impacts on any one particle is not longer than 0.05 second accompanied by an impact velocity of at least 15 meters per second.

Still, more particularly, this invention relates to a method for preparing fine grain materials for use in casting, building or making of structural or modular elements, such as blocks, bricks, panels, highway paving slabs, building components for hydrotechnical structures. columns and beams for use in industrial buildings and so forth. Besides, it makes possible production of small-size building elements such as tiles, pipes, bricks, fioor and roof slabs, etc., furthermore, the manufacture, by granulation of iron ores, of mixes for briquetting. In addition, said method aims at improving the various properties of mixes as used in the manufacture of different kinds of glass; and, by comminution, of cement and clinker, to obtain cements of improved quality; the comminution of different pulverous materials e.g. stabilizers for paints, varnishes and glues. It embraces even the comminution of corn with a view to enhance the quality of flour.

Up to now in the making of building or structural elements, such as blocks or bricks, it has been customary to utilize an aggregate of the desired size and to thoroughly mix such aggregate with a binding agent and to thereafter cast the element or article in a well-known manner. While this method is suitable for certain types of building or structural elements, the compression strength and the other physical properties of such elements are limited by the properties of the materials employed and consequently, a material increase in the compressive strength and in the other physical properties of such building or structural elements represents a material step forward in the art.

Additionally, until the advent of the processimprovements of the present invention, highly activated and homogenized mixes could not be prepared by simultaneously treating all the raw components. It will be appreciated that excellent activation homogenization of mixes is essential in preparing high-quality building materials, such as, for instance, lime-sand blocks, bricks, as well as for obtaining briquettes of adequate strength for enhancing the properties of glass and cement; for more effective comminution of clinker; to manufacture high-quality additives for paint, varnishes and glues (using silicalcite i.e. silicalime mixes, and other materials), and in corn grinding, to enhance yield and properties of flour. The prior art equipment, namely, ball mills hammer mills, vibrating means and other blending devices do not suflice.

It is accordingly an object of the invention to provide a method of preparing fine grain materials for use in casting building or structural elements which will provide a structural element having a substantially greater compressive strength and other properties than those possible so far with the same materials.

A further object of the invention is the provision of a method of preparing fine grain materials for use in casting building of structural elements which may be conveniently and economically carried out and which is conducive to a high production rate.

A still further object of the invention is the provision of a method of preparing fine grain materials for use in casting building or structural elements with resulting element having substantially greater compressive strength than was possible so far and in which the quantity of binding agent, such as lime, may be substantially reduced com: pared to conventional amounts.

A still different object of the invention is the provision of a method of preparing fine grain materials for use in the preparation of briquettes, in the production of glass and cement and in the production of additives for paint varnishes and glues, all the products being of better properties than heretofore possible for the same materials.

Further objects and advantages of the invention will be apparent from the following description taken together with the drawings in which reference numerals refer to like parts throughout:

FIG. 1. Disintegrator. Front elevation partially cut away.

FIG. 2. Disintegrator: Cross-sectional view along line AA as shown on FIG. 1.

FIG. 3. Disintegrator and rotor assembly enlarged sectional view.

FIG. 3a is an enlarged fragmentary sectional view illustrating a portion of the structure shown in FIG. 3.

FIG. 4. Cross-sectional view along line F-F shown on FIG. 3. Rotor bars of cylindrical and triangular crosssection.

FIG. 5. Cross-sectional view along line F--F shown on FIG. 3. Rotor bars of rectangular and plate-shape cross-section.

FIGS. 6 and 6a. Disintegrator rotors having bars of cylindrical cross-section. FIG. 6 being a vertical crosssectional view, FiG. 6a on the left-hand side being a crosssectional view taken along line GG of FIG. 6 and the right-hand side of FIG. 6a being an end elevation of the structure of FIG. 6 as viewed from the left.

FIG. 7. Disintegrator. Diagrammatical plan view.

FIG. 8. Partially-cut-away view along line BB shown on FIG. 2.

FIG. 8a is a sectional view taken along line L-L of FIG. 8.

FIG. 9. Partially-cut-away view along line C-C shown on FIG. 2.

FIG. 9a is a sectional view taken along line E--E of FIG. 9.

FIG. 10. Diagram of continuous process.

FIG. 11. Diagram. Continuous manufacture of mix.

FIG. 12. Diagram displaying motion of grains between two adjacent rows of bars.

' FIG. 13. Layout of disintegrator rotor bars of joint bar circle.

One aspect of the method of this invention involves thepreparation of fine grain materials which. may be utilized for casting building or structural elements, such as blocks, bricks, wall and floor sections and other mod-ular construction units and in which such elements will have a density of 1.8 kg./dm. and a compressive strength exceeding by for 2000 kg. per sq. cm., which corresponds to 28451.61 pounds-per sq. inch which is materially greater than the compressive strength heretofore provided in building elements of this nature. It has been found that such improved results'may be obtained by subjecting the particles, of the fine grain materials utilized in the building elementsto an activationby a succession of impacts of a certain velocity and within a certain time interval and as a result of such treatment, the material acquires new and previously unknown vastly improved properties.

In carrying out the method of this invention, the materials utilized are supplied in the desired proportion, in particle size not exceeding two inches in the major dimension and are subjected to successive impacts in the impact zone of the present in'ventionand the process is 1 controlled so that the time interval between two impacts on any one particle is not longer than 0.05 sec. and the impact velocity on each particle is at least fifteen meters per second. Furthermore, it has been found that the number of such impacts .on each particle should not be less than three. It is pointed out that'the method of this invention may be carried out as a continuous process or may be utilized in connection with a batch process, but for economyof operation and where relatively large scale production is required, the continuous process is, of course preferred.

It has also been found that in practicing the method of this invention thata more thorough mixing of these materials occurs than was heretofore possible with conventional methods and this is particularly advantageous when mixing a binding agent, suchas lime with the materials, since this more thorough mixing results in a complete coating of each particle of the aggregate by the binding agent necessary to provide a material having the improved qualities mentioned above. Furthermore, the method of this inventionmay be carried out in a moist atmosphere or with a water addition which will result in providing a material which may be charged directlyinto a mold, thereby eliminating the necessity for an intermediate mixing step or operation.

As illustrative of the invention, the method of this invention may be utilized in connection with a mixture of sand and lime to provide a material for forming high quality silica block articles which possess improved qualities and provide a compressive strengthof substantially more than'ZOOO kg. per sq. cm. The improved results obtained by the method of this invention flow directly from the provision of rapid impact at an impact velocity of not less than fifteen meters per second on each particle of the material and with the time interval between impacts limited to not longer than 0.05 second and for best results, there should be at least three such impacts.

It should be noted that the application of this method is not limited to the use of only some specific types of material, or materials of definite grain size, but is applicable with any kind of material the properties of which are enhanced in the process, the only provision being that the grain not exceed 2 in. in major dimension.

Suchprocessing of materials embraces grains of any size, the finest included, ie of the order 1.1 microns radius. Owing to this,,loess, pozzolan and various kinds of ash are rendered more active, resultingin raw materials of adequate quality for use in building structures.

Such processing causes changes in the geometricalshape of the .grains, simultaneously improving their physical and diffusion properties. The particles of different stones, basically composed of A1 0 or Fe O or the like rangement utilized in accomplishing the method of the' present invention. It will be noted that the distintegrator or comminutor includes rotors as impacting means which are enclosed in a casing, having rotating means with perpendicularly positioned bars arranged along intermeshed concentric circles to defineor' constitute an impact zone. In the machine of the presentinvention, the bars of the rotary means are spaced so as not to permit the travel of material grains across the trajectory of each other row without impacting or colliding with the bars thereof (see FIG. 12 and FIG. 13).

On the basis of geometrical considerations it can be found every particle of radius 6 will'collide with at least one barin every circular row of bars when the maximum spacing between the bars of a circular row m is defined by the following formula produced by the inventor in realizing his invention:

where (P P =maximum spacing between centers of two adjacent bars of bar circle m, in cm.;

R =radius of bar circle, .mi in cm.;

R =radius of bar circle m-l, in cm.;

r=radius of bar, in cm.;

rl ;number of rotations of bar circle rn, in r.p.m.;

n =number of rotations of bar circle -1, in r.p.m.;

5=radius of grain of materialv to be processes, in cm.

This formula is applicable for those types of disintegrators as specified here in this inventionrlnpractice, this formula has been used for disintegrators with the radius R of the outermost bar circle varying within the limits l10*90O mm, the radius r of the bars varying in the range 340 mm, and the distance a-l-d between centers of two adjacent bars on a bar circle varying within the limits 17-250 mm. the rpm. varied in the range.400'4500 and the radius of the grains of the material to be processed varied within the limits 01-25000 i.e. having a diameter or major dimension of from .2 microns to, two inches.

It must be noted also that the concentric circles of bars are radially spaced each other preferably at a distance comprised in the range 10-250 mm., the number of said circles is preferably comprised in the range 3-8 and the number of bars on each circle is preferably comprised in the range 850.

To obtain a fine-grain material with properties as specified hereinbefore, the diameters, r.p.m., and number of bar circles, ofboth the external and internal rotors, must be chosen so as to ensure at least three successive impacts on any one particle, with a maximum interval between two successive impacts not exceeding 0.05 see. In addition, the peripheral velocity of the innermost bar circles (of boththe external and the internal rotor) must be above m./sec. Ergo, the rotations per second of the smallest bar circle of radius R must be above ii 21rR By referring to the drawings the design of the disintegrator will be better understood. FIG. 1 shows the disintegrator to have two rotors.

The inner rotor 1 is located on a stationary frame 2, While the travelling frame 4 holds the outer rotor 3.

Rotor bars 6 are positioned concentrically on disk 5 of inner rotor 1. Disk 7 of outer rotor 3 is also equipped with concentrically positioned bars. FIG. 1 and FIG. 3 show rotor bars of round cross-section, but bars may differ in cross-section, e.g. being rectangular or of other shape as shown on FIGS. 4 and 5, in which event the radius of each bar is that of a circle which circumsoribes the particular shaped bar. v

The disintegrator rotors 1 and 3 mounted on their respective shafts 8 and 9 have opposite rotation, to attain higher relative peripheral velocities and to prevent the rotors being destructed by the material processed, as may occur in commin-utors having one rotating and one stationary rotor.

In the preparation of mixes to be used in casting building materials an empirical relationship has been found between certain elements of the disintegrator, the way of operation, and the degree of activation (increase in the specific surface of the mix caused by processing in the disintegrator); the degree of activation is in turn tied, by another relationship, to the physical characteristics of the finished building element.

These relationships permit a very convenient way of controlling the process.

To ensure the proper flexibility of operations it has been found expedient to equip the disintegrator either with multispeed A.C. motors, or DC. motors having adjustable speed ranges, which permit the changing of disintegrator rotor speeds according to the required degree of activation.

Either by choosing a disintegrator of suitable size, or by rotor speed adjustment, the desired degree of activa- D =dia. of bar circle, last but one. N =r.p.m. of bar circle, last but one. N =r.p.m. of last bar circle. D =diameter of last bar.

If in Formula 2 Percent: Mm. 41.6 1.2-0.6 52.1 0.6-0.3 5.7 0.3-0.15 0.5 0.l5-0.1 0.1 0.1

This sand has a SiO content of 95% The value of c is: c=63.l0

As was mentioned, above the capability of a mix to give a certain finished building element is tied to its degree of activation 2. In general, the quality of the mix is directly proportioned to the value e. The strength of silicalcite products in which sand having a quality index 1.0, depending on value c is found by the empirical formula:

e-a A-e-a+B 4) where R=strength (kg/cm?) of product having a density 1.8

g./c-m. I g

A and B=empirical coefficients, depending on the autoclaving procedure. A and B are obtained in the table below.

Steam pressure and curing temperature Duration of Steam 2 at (133) 6 at. (164) 10 at. (183) 16 at. (203) 25 at. (225) Curing, hrs.

A10 B A.10* B A10 B A10 B A10 B tion is attained, which is found by the following empirical formula:

terial;

( mean =the mean value of the ratios of maximum permissible spacings between centers lines of two adjacent bars (i.e. means value of all bar circles), divided by the distance between centers of bars (see also definitions in Formua=bar spacing in cm. (see FIG. 13). d=diameter of bar in cm. (see FIG. 13). G=quantity of materials to be processed. N D =is determined by the formula:

Brakes 12 and 13 are provided on the shafts 8 and 0 of the disintegrator.

The inner rotor shaft 8 passes through bearing housing 14. The drive motor 10 and brake 12 are mounted on the main frame 2.

The 'outer rotor shaft 9, bearing housing 15, drive motor 11 with brake'13 are mounted on the travelling frame 4. Bi-directional travel of the latter is effected by spindle, air cylinder or other means 16. The fixing device 17 provided on the travelling frame allows it to be locked in either of its extreme positions, i.e. with the rotors close, or with the rotors completely apart.

The disintegrat-or rotors are incorporated in a jointhousing comprising body 18 and top cover 19, as shown in drawing 2. The end cover 20 of the housing located at the right-hand of the disintegrator is mounted on travelling frame 4. The housing body 18 is secured to the main frame. The top cover 19 being opened or closed either 7 v by means of pneumatic or hydraulic cylinder 21, turns about its articulated joint 22.

Packing 29 (see FIG. 3) of foam-rubber or other resil-- the space embraced by the rotors. Part of the water nec-,

essary for moulding may be fed into the disintegrator along piping 26 (see FIG. 7).

The production of silicalcite products according to the present invention could be done as shown in FIG. 10.-

In accordance with the scheme of FIG. 10, all operations of grinding and making mixes are effected by a single apparatus. Thus high activation and homogenization of every mixture constituent is warranted, resulting in' high quality products.

It should be noted that the use of this invention eliminates the need of any additional equipment such as special blending units, water feeders, mixers for aluminium powder or other additives to be used in the silicalcite mix.

Therefore no provision has been made for anykind of transport facilities carrying dry mixes to such units or finished mixes from them to moulding units.

Owing to this the process of manufacturing mixes is extraordinarily simple, inexpensive and readily adapted to comprehensive automation.

The example below, based on the technological diagram, has been included. to illustrate the arrangement of technological equipment as used in the manufacture of silicalcite.

Raw materials supplied at the plant (lime or ashes, etc., sand or pozzolan or loess or ashes etc.) are delivered into the hoppers 31-32. Other components (aluminium-v powder, pigments etc.) are conveyed into hoppers 33. The disintegrator 40 issupplied with raw materials from hopper 31-32, water. being fed in one with lime slaking retarders coming from tank 34, along corresponding wa-. ter piping. At the same time aluminium powder, pigments and other materials arebeing dosed from hoppers 33 in quantities and ratios required, into the disintegrator 40. This is effected by the automatic controlled continuous dosers 35; 36; 37; 38 and 39. The degree of activation of the various components, differing for separate mixes when manufacturing different kinds of products, is controlled by varying the rotative speed of the disintegrator rotors from-the central control panel. The latter located in close vicinity of the moulding site accommodates all accessories and devices required .in controlling the supplying of raw materials, conveying operations, proper dosing of ingredients, the equipment used in pouring or placing mixes, shifting moulds etc. In addition, all signalling devices and checking instruments are conveniently grouped on this control panel.

The various operations are controlled either automatically or by the operator.

Trolleys together with moulds which have been refitted and prepared and have reinforcement positioned as per design, are carried by crane 43 from the mould stripping shop either to conveyer 41 for solid products, or to conveyer 42 for foamed products.

The activated and homogenized mix passes out of the disintegrator onto. a reversible conveyer 44 for distribution as follows:

Trolleys with moulds are passed on by conveyer 42 and reversibleintermediate conveyer. 47 and positioned under the mix discharge chute 45. The intermediate conveyer 47 is equipped with a mechanism for compacting the mix by vibration. If making mixes for cellular products, conveyer 44 operates in direction A and the: mix ispoured through chute into the mould 46.

When the moulds have been filled to the proper level the trolley is transferred to conveyer 42 and passed, along to the track where solidification occurs.

With the conveyer 44 operating in direction B the mix for solid products is delivered into the hopper of the.

movable mixture placer 48 for conveying to the vibroplatform 49, or by other means of conveyance to the corresponding units for making sewage pipes, roof tiles etc.

After solidification the moulds containing cellular mixes are subjected by a special unit 50. When required, device 51 is employed in cutting the solidified green prod-. not into components differing in size. Waste material due to screening is transferred into the sand'hopper and together with sand they are fed againinto the disintegrator.

Crane 52 transfers the moulds containing green products to autoclave trolleys which are then collected into trains 53. Emptied trolleys are shifted to conveyor 55 and passed along to crane 43.

Solid mix in moulds transferred by conveyor 41 to vibrostand 49 are lifted onto the vibrostand by crane .52.

Having been compacted by vibration the mix in moulds is loaded on autoclave trolleys 53. The trolleys that have been unloaded are transferred to conveyer 55 and are returned .to crane 43.

Such a continuous technological procedure vis not limited to only the production of silicalcite, but is also applicable in the manufacture of products other than silicalcite.

Another variant based on the same principle is that of subjecting one ingredient of the mix, say sand, to disintegrator processing, and using another disintegrator to make the mix;,to make the mix in the same disintegrator subsequent to sand processing.

Since some of the concepts and the basic principles of of, but by no means limiting the invention- Example 1 Raw materials used:

(a) Standard silica sand of the sand-pit Quartz, Si0 content 95%, specific surface 100 cm. /g.; (the specific surface was measured by means of the Blaine apparatus).

(b) Powdered slack lime, active CaO content (c) Water.

The constituents were closed into the disintegrator, the percentage content of active CaO in the mix being 10% with the moisture 16%. (All the percentages in this and in the other examples are given on the basis of the weight of the dry mix). Degree of activationin processing (see Formula 2), e=300 cm. /g.; impact velocity m./sec. 5 impacts.

After processing the mix was placed into moulds and vibrated at a frequency 3000 c./sec., amplitude 0.5 mm., duration 1.5 min.

Green products were autoclave-cured 8 hrs. at 12 atg.

pressure. Density of finished productl78 t./m. compressive strength 450 kg./cm.

Example 2 Raw materials used: same as in Example 1. The constituents were dosed into the disintegrator, the percentage content of active CaO in the mix being 12% with the moisture 13%.'Degree of activation in processing (see Formula 2).

e=350 cm. /g.; impact velocity m./sec., 5 impacts.

Example 3 Raw materials: same as in Example 1.

The constiuent were dosed into the disintegrator, the percentage content of active CaO in the mix 18.5%, with 8% moisture. Degree of activation in processing (see Formula 2).

e=1400 cm. /g.; 7 impacts at velocity 160 m./sec.

Density 1.85 t./m. required moulding pressure 320 kg/cmP.

Green products were autoclave-cured 10 hrs. at a pressure 12 atg.

Compressive kg./cm.

strength of finished product 1930 Example 5 Example 6 Raw materials: same as in Example 1.

The constituents were dosed into the disintegrator, the percentage content of active CaO in the mix 22.0%, with moisture. Degree of activation in processing (see Formula 2).

e=1800 cm. /g.; 7 impacts at velocity 200 m./sec.

Density 1.90 t./m. required moulding pressure 550 kg./cm.

Green products were autoclave-cured 16 hrs. at a pressure 12 atg.

Compressive strength of finished product 3250 kg./cm.

Example 7 Raw materials used:

(a) Standard silica sand, SiO content 95%, specific surface 100 cm. /g.;

(b) Ground quick lime, active CaO content 90%.

(c) Powdered slack lime, active CaO content 70%.

(d) Water.

(e) Aluminium powder.

All constituents were dosed into the disintegrator, the percentage content of active CaO in the mix 22%, of which 2/ 10 were due to slaked, and 8/10 to quick lime, water content in mix 48%, aluminium powder 0.13%.

Degree of activation in processing (see Formula 2).

e=l800 cm. /g.; impacts at velocity 180 m./sec.

The processed mix was moulded by pouring into metal moulds. After solidification the green products were autoclave-cured 11 hrs. at a pressure 12 atg. Density of resultant products 0.41 t./m. compressive strength 45 kg./cm.

10 Example 8 Raw materials used: same as in Example 7.

All constituents were dosed into the disintegrator, the percentage content of active CaO in the mix 22%, of which 3/ 10 were due to slaked, and 7/10 due to quick lime; water content in mix 42%, aluminium powder 0.09%.

Degree of activation in processing (see Formula 2) e=1800 cm. /g.; 8 impacts at velocity 180 m./sec.

The processed mix was moulded by pouring into metal moulds. After solidification the green products were auto clave-cured 12 hrs., at a pressure 12 atg.

Density of resultant products 0.62 t./m. compressive strength 125 kg./cm.

Example 9 Raw materials used: same as in Example 7.

All constituents were dosed into the disintegrator, the percentage content of active CaO in the mix 20%, of which 4/10 was due to slaked, and 6/10 due to quick lime; water content in mix 33%, and aluminium powder 0.04%.

Degree of activation in processing (see Formula 2) e=1600 cm. /g.; 7 impacts at velocity 180 m./ sec.

The processed mix was moulded by pouring into metal moulds. After solidification the green products were autoclave-cured 12 hrs., at a pressure 12 atg. Density of resultant products 0.95 t./m. compressive strength 325 kg./cm.

Example 10 Raw materials used: same as in Example 7.

All constituents were dosed into the disintegrator, the percentage content of active CaO in the mix 20%, of which 4/ 10 was due to slaked, and 6/10 due to quick lime; water content in mix 28%; and aluminium powder 0.015%.

Degree of activation in processing (see Formula 2),

e=1500 cm. /g'.; 7 impacts at velocity 140 m./sec.

The processed mix was moulded by pouring into metal moulds. After solidification the green products were autoclave-cured 12 hrs., at a pressure 12 atg. Density of resultant products 1.20 t./m. compressive strength 510 kg./cm. 1

Example 11 Raw materials used:

(a) Sand, Si0 content 76%, initial specific surface 60 cm. /g.;

(b) Lime, active CaO content (c) Powdered slack lime, active CaO content 70%,

((1) Water,

(e) Foam-builder composed of about 60% carpenters glue, and about 40% colophony soap.

The constituents were dosed into the disintegrator, the percentage content of active CaO in the mix 18%, of which 3/10 was due to slaked, and 7/ 10 due to quick lime; moisture 30%, the foam-builder was 0.015%.

Degree of activation in processing, e=1300 cm. /g.; 5 impacts at velocity 140 m./sec.

The foam-builder was introduced into the mix g. per 1 m5 dry ingredients, and thoroughly blended in a special continuous mixer.

The green products were autoclaved-cured 9 hrs., at a pressure 12 atg. Density of resultant products 1.12 t./m. compressive strength 310 kg./cm.

Example 12 Raw materials used:

(a) Sand, SiO content 76%;

(b) Powdered slaked lime, active CaO content 70%;

(c) Water.

The constituents were dosed into the disintegrator, the active CaO content in the mix was 12% with 13% moisture.

Degree of activation in processing, e=700 cm. /g.; 5 impacts at velocity 80 m./sec.

The mix was molded by vibro-pressing; vibration frequency 3000 c./min., amplitude 0.45 mm., moulding pressure 6.5 kg./cm.

The green products were autoclave-cured 9 hrs., at 12 atg. pressure. Density of finished products 1.92 t./m. compressive strength 1080 kg./cm.

Example 13 Raw materials used:

(a) Sand,.SiO content 66.2%, initial specific surface 420 cm. /g.;

(b) Ground quick lime, active CaO content 80%;

(c) Powdered slack lime, active CaO content-58%',

(d) Water;

(e) Aluminium powder.

By appropriate proportioning the constituents the mix obtained an active CaO con-tent of 75%, where 3/ 10 was due to slaked, and 7/ 10 due to quick lime. Moisture of mix 31%; aluminium powder 0.20%.

Degree of activation in processing 500 cm. /g., 5 imparts at velocity 120 m./sec.

Green-products were autoclavecured 10 hrs. at a pressure 10 :atg. Density of finished product 1.12 t./m.' compressive strength 210 kg./cm.

Example 14 The mix was poured. The green products were autoclave-cured 12 hrs, at'10 atg. pressure.

Density of resultant products 0.97 t./m. compressive strength 205 kg./cm.

Example 15 Raw materials used:

(a) Sand, SiO content 65.8%; initial specific surface 300 cm /g.;

(b) Powdered slack lime, active CaO content 52%;

() Water.

The constituents were closed into the disintegrator in proportions yielding a mix of 12% active CaO content, moisture 18%.-

Degree of activation in processing 200 cm /g, impacts at velocity 80 m./ sec.

The mix was moulded by vibration at a frequency 3000 c./min., amplitude 0.6 mm., duration 2 min.

The green products were autoclave-cured 8 hrs, at atg. pressure.

Density of resultant products strength 370 kg./cm.

1.63 t./m. compressive Example 16 Raw materials used:

(a) Loess, Si0 content 54%, initial specific surface 3500 cm. /g.;

(b) Powdered slack lime, active CaO content 50%;

(c) Water.

The constituents were dosed into the distintegrator in proportions yielding a mix of 16% active CaO content, moisture 10%.

Degree of activation of the mix in processing 2:300 cm. /g.; 6 impacts at velocity 80 m./sec.

The products were moulded by pressure to a density 1.8 t./rn. and were autoclave-cured 10 hrs, at 10 atg. pressure. Compressive strength of resultant products740 kg./cm.

Example 17 Raw materials used:

(a) Loess, SiO content 54%, initial specific surface 3500 cm. /g.;

(b) Ground quick lime, active CaO content 60%;

(c) Powdered slack lime, active CaO content'48%;

(d) Water;

(e) Aluminium powder.

The constituents were dosed into were due to slaked, and-,7/ 10 to quick lime.

Degree of activation in processing e=l150 cm. /g.; 6 impacts at a velocity m./ sec.

The products were moulded by pouring into metal moulds and were autoclave-cured 10 hrs., at 8 atg. pressure.

Density of resultant products 1.18 t./m.

Compressive strength 220 kg./cm.

Example 18 Example 19 Raw materialsused:

(a) Clay sand, SiO content 48%, clay content 22%; initial specific surface 1040 cm. /g.;

(b) Ground quick lime, active CaO content 70%;

(c) Powdered slack lime, active CaO content. 55%;

(d) Water;

(e) Aluminium powder.

The constituents were dosed into the disintegrator in proportionsyielding a mix of 17.5%, of which 3/ 10 were due to slakedand 7/10 due to quick lime. Moisture 43 aluminium powder 0.10%.

Degree of activation of the mix in processing e=400 cm.' /g.-; 5 impacts at a velocity 120 m./sec. The products were moulded by pouring into metal moulds'and autoclave-cured 8 hrs. at 10 atg. pressure.

Density of resultant products 0.59 t./m. compressive strength 45 kg./cm.

Example 20 Raw materialsused: same as in Example 19.

The constituents were dosed into the disintegrator in proportions yielding a mix of 17.5% active CaO content, of which 3/ 10 were due to slaked, and 7/ 10 due to quick lime. Moisture 43% and aluminium powder 0.035%.

Degree of activation of the mix in processing e=400 cm. /g.; 5 impacts at a velocity 120 m./sec.

The products were moulded by pouring into 'metal moulds and autoclave-cured 8 hrs. at 10 atg. pressure.

Density of resultant products 0.93 t./m. Compressive strength 120 kg./cm.

I the disintegrator in. proportions yielding a mix of 19.5%, of which 3/ 10 were 1 3 Example 21 Raw materials used: same as in Example 19.

The constituents were closed into the disintegrator in proportions yielding a mix of 17.5% active CaO content, of which 3/10 were due to slaked, and 7/10 due to quick lime. Moisture 43%, aluminium powder 0.020%.

Degree of activation of mix in processing e=400 cm. /g.; impacts at a velocity 120 m./sec.

The products were moulded by pouring into metal moulds and autoclave-cured 8 hrs. at 10 atg. pressure.

Density of resultant products 1.08 t./m. compressive strength 205 kg./cm.

Example 22 Raw materials used:

(a) Sand, SiO content 82%; initial specific surface 200 cm. /g.;

(b) Carbide waste, active CaO content 46.3%;

(c) Water.

The constituents were dosed into the disintegrator in proportions yielding a mix of 14% active CaO content; moisture 9%.

Degree of activation of the mix in processing e=320 cm. /g., 5 impacts at a velocity 80 m./sec.

The products were moulded by pressing to a density 1.8 t./m. and autoclave-cured 8 hrs. at 8 atg. pressure. Compressive strength of resultant products 590 kg./cm.

Example 23 Raw materials used: (a) Iron ore powder of a composition as follows:

Percent FeO 24.75 Fe O 55.17 CaO 3.20 MgO 0.62 SiO 16.85 S 0.04

Initial specific surface 790 cm. /g.

(b) Powdered slack lime, active CaO content 48%.

(c) Water.

The constituents were dosed into the disintegrator in proportions yielding a mix of 4.4% active CaO, moisture 7%.

Degree of activation of mix e=200 cm. /g.; 5 impacts at velocity 60 m./see.

The products were moulded by applying 200 kg./cm. pressure and autoclave-cured 4 hrs. at 10 atg. pressure. Density of resultant products 2.54 t./m. compressive strength 245 kg./cm.

Example 24 Raw materials used: same as in Example 23.

The constituents were dosed into the disintegrator in proportions yielding a mix of 4.4% active CaO content, moisture 7%.

Degree of activation of mix in processing e=200 cm. /g.; 5 impacts at a velocity 60 rn./sec.

The products were moulded by applying 800 kg./cm. and autoclave-cured 4 hrs. at 10 atg. pressure. Density of resultant products 2.70 t./rn. compressive strength 415 kg./cm.

Example 25 Raw materials used: same as in Example 23.

The constituents were dosed into the disintegrator in proportions yielding a mix of 5.6% active CaO content, moisture 7.5%.

Degree of activation of the mix in processing e=450 cm. g.; 5 impacts at a velocity of 120 m./sec.

The products are moulded by applying 200 l g./cm. pressure, and autoclave-cured 4 hrs. at 10 atg. pressure.

Density of resultant products 2.67 t./m. compressive strength 350 kg./cm.

Example 26 Raw materials used: same as in Example 23.

The constituents were dosed into the disintegrator in proportions yielding, a mix of 5.6% active CaO content; moisture 7.5%.

Degree of activation of the mix in processing e=450 cm. %g.; 5 impacts at a velocity of rn./ sec.

The products were moulded by applying 800 kg./cm. pressure and autoclave-cured 4 'hrs. at 10 atg. pressure.

Density of resultant products 2.87 t./m. compressive strength 567 kg./cm.

I Example 27 Raw materials used: same as in Example 23, but without using lime.

The iron ore concentration was processed in the dis integrator adding water in required amount (6%), at a degree of activation e=300 cm. /g.; 6 impacts at a velocity 70 m./sec.

The products were moulded by applying 200 kg./cm. pressure and autoclave-cured 4 hrs. at 10 atg. pressure. Density of resultant products 2.64 t./m. compressive strength 287 kg./cm.

Example 28 Raw materials used: same as in Example 23, but without using lime.

The iron ore concentration was processed in the disintegrator adding water in required amount, (6%) at a degree of activation e=300 cm. g. 6 impacts at a velocity 70 m./sec.

The products were moulded by applying 800 kg./cin. pressure and autoclave-cured 4 hrs. at 10 atg. pressure.

Density of resultant products 2.84 t./m. Compressive strength 503 kg./cm.

Example 29 Natural said containing SiO 90%; CaO, 3%; MgO, 2%; A1 0 2%; Fe O 3% and Portland cement, grade 400 according to GOST-31060 (U.S.S.R. Government Standards).

In processing both constituents in the disintegrator, the impact velocity of particles was 40 m./sec. with every particle subjected to 3 impacts. The weight ratio of sandcement was 1:3. Both constituents treated were in dry condition.

After disintegration water was introduced into the mix so as to make the water-cement ratio 0.4.

From this mix cylinders were moulded by pressing, and attained a density 1.8 g./cm.

The test specimens were subjected to different conditions of hardening:

(a) In a steam chamber at a temperature 90 16 hrs.

(b) In water-28 days.

Mixes were also made using the same natural sand and the same grade of Portland cement in proportions as above, and by the method prescribed by the Standard Specifications for Determination of Cement Grade. (GOST 310-60.) The test specimens were subjected to similar conditions of hardening. Test specimens made from nondisintegrated mixes and having hardened in the steam chamber attained a compressive strength 219 kg./cm. whereas specimens made of disintegrated mixes, and having hardened in like conditions, displayed a compressive strength 333 kg./cm. The compressive strength of water cured specimens, made from conventional mixes, was kg./cm. against the compressive strength 282 kg./cm. of water cured specimens made from disintegrated mixes.

Example 30 Raw material used:

Natural sand having a granulometric composition as follows:

and Portland cement grade 400.

The particles of both raw materials processed in the disintegrator were subjected to, 3 impacts each at the velocity 45 m./ sec. Themix moistened to the water-cement ratio w./c.=0.4,,was used in moulding cubes, which were vibration-compacted. Density of cubes 2.02 g./cm.

Other mixtureswere made in the conventional manner prescribed by the Cement Grade Specifications (GOST- 310-60) and using the same grade of cement and the same natural sand. The density of these vibration-compacted cubes equalled 1.93 g./cm.

Both, the cubes made from disintegrated mixes and those made from conventional mixes, were simultaneously subjected to hardening in one and the same steam chamber for 24 hours.

The cubes made from disintegrated mixes attained a compressive strength 555 kg./om. against the compressive strength 265 kg/crn. of the cubes made from non disintegrated mixes.

Example 31 (GOST-310-60). The raw-materials used, i.e. sand andv cement where the same, and corresponding in all properties to those mentioned above. Hardening conditions were alike for both'kinds of specimens. The specimens made from disintegrated mixes, displayed a compressive strength 282 kg./-cm. whereas those made from conventional mixes, attained a compressive strength of only 198 kg./cm.

Example 32 A sample of wheat, 772 g./e., containing: moisture 14.2%, ashes 1.76%, mineral admixtures 0.1%, organic admixtures 2.7%, gluten 24.3%, glassiness 37%.

In grinding the wheat a disintegrator and an industrial wheat mill were used. Results obtained are shown below (once through):

Disintegrator Industrial mill 73% 36%. Ashes 0.48% 0.53%. Quality of b d made of the respective flour:

Bread, yield per 100 g. flour 0.5 litres 0.46 litres. Height-dia., ratio of bread, hld- 0.46. Degustation test results on bread 27 points 24 points.

quality.

l 5 Example 33 Piecesof gas silicalcite (i.e. cellular silicalcite) made from disintegrator-processed sand-lime mixes, containing 15% active lime CaO and sand, and autoclavecured 12 hours at, 10 atg. pressure were used. Their density equalled 0.9 g./cm.

By crushing the gas silicalcite pieces chips were obtained, whichdid not exceed 10 mm. in size. Further, the chips fed into the disintegrator by continuous dosing were subjected to 7 impacts each at an impact velocity 180 m./ sec. After processing, the resultant particles were found to have a specific surface 1800 cm. /g., as deter-v mined by means of Blaines apparatus.

Next, the powdered silicalcite was put through a sieve, mesh dia. 0.088 mm. The residue retained on the sieve was again disintegrator-treated.

After sieving the silicalcite powder, in 20% amounts was added to such paints, varnishes andglues'as listed here: oil paints (some containing natural boiled linseed oil) others--synthetic drying oil, e.g. obtained from shale oil called oxol, varnishes epoxide-resin, glues, glue DFK and so forth.

Test data thus far obtained show that owing to the addition in 20% amounts of silicalcite powder, activated in the disintegrator, the said paints, varnishes and glue show improved polymerization and dry twice as rapidly as compared with such not c-ontainingsilicalcite powder. In addition to enhanced abrasion resistance (2-5 times) the paints and varnishes displayed an-increase, by 2 to 3 times, in weather resistance. The bonding strength of epoxide-resin glues and that of DFK type glue was increased by 2-3 times with a 60% decrease in expenditure.

In the. above, specific information has been provided as to both the disintegrator used in the concept of the present invention. However, some comment must be set forth regarding the utilization of the disintegrator of the presentv invention and the specific parameters set forth in the above. It has been observed that many properties of the sand due to the present treatment are varied over the grinding techniques of sand as accomplished by prior art devices, such as ball mills and vibration mills. It should also be pointed out that the present invention does not pertain only to the treatment of sand in conjunction with a binder, but, relates to the treatment of sand in comparison of the ,cornminuting techniques of sand in the device of the present invention, grinding mills of the type known as ball mills and vibration mills. It

has been established that sands ground in thevarious machines differ from each other in a number of ways.

In a disintegrator each grain of sand is made smaller independently of the other grains by impacts against the disintegrator members. When the sand is ground in this way the particles obtained are of an identical shape for any fineness of grinding. In a ball mill, the large grains are the first to be ground. In a vibration mill the large grains are abraded'due tothe small force of the impacts.

In the particles of sand ground in a ball. mill at high percentage of the measured angles between the plane faces of the grains approximate while in sand ground in a disintegrator of the present invention the number of such angles is half of this value.

Additionally, it was discovered that there is considerable of the grinding techniques of the present invention as compared to prior art methods, in the granulometric composition of sand that was ground by prior art methods and the present method.

For instance, this can be-readily seen from Tables 1 and 2.

TABLE 1 The processes of grinding in various machines can be studied with the aid of the functions of grinding. Such Grinding machine Dish} Ban mm vibrator functions of grinding for the sands are given in Table 2. t s H1111 Prior art workers used to determine the functions of grinding by considering the changes in the grain com- Number of grains v 1 micron in size. 221 287 291 osition de endin on the duration of rindin s ill Number of plane faces 455 397 459 h d A w Number of lane faces er grain (avere S own 6 ow, t e sari grains are in e slntegrator age) Z06 for only fractions of a second, and even this duration Percentage of area of plane faces over the total area 515 m 18.07 16.4 12.2 depends on the number of revolutrons of the peg rotors. Number of angles 157 133 151 Numberofanglespmgm M1 M6 The greater the number of revolutions. of e p s, th faster the processing of the sand grams 1n the disintegrator and the finer the grinding. For this reason, grinding in a TABLE 2 Content of fractions in sand, percent Specific Specific surface of surface of particles contained in Index Sand fractions, mm. in size sand, sq. sand, less than 0.1 mm.

crn./g. in size (pulverized) sq. em/g. 1. 2-0. 6 0. 6-0. 3 0. 3-0. 015-0. 10 0. 10-0. 05 0. 05-0. 01 0.1-0

Norn.l\leanings of the column Index:

1-No grinding (natural sand).

2Grinding in the disintegrator O/1,988 r.p.m.

3Grinding in the ball mill during 0.1 hr.

4 Grinding in the vibration mill during 2 min.

5Grinding in the disintegrator 2,870/3,550 r.p.m.

6-Grinding in the ball mill during 4 hrs.

7Grinding in the vibration mill during 7 min.

Now, let us consider the distribution of the sand by fractions depending upon its specific surface and in relationship to Table 2 stated in the above. For grinding in a disintegrator the results if plotted in a graph will show curves of the various sand fractions which are of the same shape. This is the result of all the fractions of the sand being crushed by the disintegrator, irrespective of the grain sizes.

As the fineness of grinding grows in any of the machines, the number of particles of the under 0.01 mm. fraction increases. Grinding in a disintegrator yields the smallest number of such particles, while a greater fineness of grinding results in their almost linear increase. When sand is ground in a ball mill and a vibration mill to a specific surface of about 800 sq.cm./g., the number of particles of this fraction rapidly grows, while with a further increase in the fineness of the sand their growth is reduced, the decrease in the ball mill taking place to a greater extent. The phenomenon of the sharp decrease in the formation of fine particles in a ball mill for great fineness of the grinding can be explained by the formation of new larger particles out of the crushed fine particles.

The above results fully conform to those obtained when determining the specific surface of particles under 0.1 mm. in size (dust). As can be seen from the data in Table 2, for grinding in a disintegrator an increase in the specific surface of the sand also leads to a greater specific surface of the dust. For grinding in a ball mill and a vibration mill the specific surface of the dust, beginning with a fineness of sand grinding of 900 sq./cm./g., does not practically increase. This will remain true until the whole batch is crushed to a size of the particles of under 0.1 mm.

8-Grinding in the disintegrator 6,888/3,550 r.p.n1. 9Grinding in the ball mill during 7 hours. 10-Grinding in the vibration mill during 9 min. 1l-Grinding in the disintegrator 4, 592/5822 r.r.m. 12Grinding in the ball mill during 10 hrs. 13Grinding in the vibration mill during 12 min. 14Grinding in the disintegrator 10,906/3,550 1.p.m. l5-Grlnding in the ball mill during 20 hrs. 16-Grinding in the vibration mill during 20 min.

disintegrator cannot be evaluated by its duration. Taking this into consideration we having compiled the functions of grinding depending on the value of the specific surface of the sand for all the three machines, namely disintegrator, ball mill and vibration mill. In this way, information has been obtained with easily comparable results. As can be seen from Table 2, there exists alinear relationship between the specific surface of the ground material and the duration of grinding when the latter is done in a ball or a vibration mill. The law of linear relationship between the specific surface of the ground material and the amount of electric power consumed per unit of weight of the ground material also holds for comminnting in a disintegrator.

When comminuting sand in a disintegrator, the part of the specific surface related to the fine fractions is smaller than for sand ground in a ball mill or in a vibration mill. A study of the various functions of sand grinding has shown that in a ball mill the large grains are primarily ground and therefore the contents of the large fractions in the ground sand are considerably lower than when grinding sand to an equal specific surface in other installations. A ball mill yields a great number of fine fractions. A vibration mill primarily grinds small size sand grains. The large grains remain intact even when grinding to a high specific surface.

In a disintegrator as a result of strong impacts of the members, the large structurally weak grains are the first to be crushed. Small size grains have a relatively greater strength and hence even with a greater force and intensification of grinding they are only slightly broken up. As a result of grinding sand in a disintegrator a number of very fine fractions obtained is smaller than when grinding in a ball mill or in a vibration mill.

Sand grains of an identical chemical and mineralogical composition may have a different structure and con- 28 the sand in a disintegrator raises its structural strength to 84%, while grinding in a ball mill orv in a vibration mill reduces it to 63% and 54% respectively. The pressing of sand in a mold raises the structural strength of rain cracks, depending on the conditions of their forma- 5 all the sands. The structural strength of disintegrated sand tion. Grains with a large number of cracks are easily after compression reaches 93 TABLE 3 Machine in which Specific surface before Specific surface after I Structual strength, Specific surface after Structual strength of sand was ground compression, first compression, Percent second compression, sand pressed once,

sq. cm./g. sq. emJg. sq. cm./g. percent Natural sand from the sand-pit Quartz 106 149 71 187 80 In a disintegrator 352 420 84 452 93 In a ball mill 286 450 63 534 84 In a vibration mill 255 470 54 653 72 split under mechanicalaction. Directly related to the strength of the sand'structure is its comminuta-bility of the magnitude of the increase in the specific surface under fixed conditions of grinding.

The structural strength of sand can be determined by the following method:

The grain composition of the same and its specific surface are determined by sieve analysis of a sand sample, and on the basis of data on specific surface of the separate fractions. Then a part of the sand sample is poured into a metal cylindrical mould and the sand is compressed withthe aid of a cylinder piston under the pressure of a hydraulic press. The pressed sand is then extracted from the mould and its grain composition and specific surface are determined.

We have named the percentage ratio of the specific surface of the initial sand to the specific surface obtained after pressing as fthe structural strength of sand,

Structural strength= The experiments for determining the structural strength. of the sand were performed in cylindrical moulds 4.25 cm. in diameter. One hundred grams of sand were poured into the mould. Pressing was carried out twiceat a pressure of 625 kg. sq./cm. After the first compression the sand was poured out of the mold, 'its specific surface Was determined once more. The results of the experiments are given in Table 3.

The structural strength of the natural sand from the For a further test method, equal quantities by weight of sand ground in the various machines are placed in cubic molds 7 X 7 X 7 cu. cm. in size. As the volumetric weight of sand in a compressed and a loose state is different, it is easy to fill cubes of the same volume with equal quantities of sand by weight, but having a difierent granulometric composition. Thus, the various kinds of sand in the sample cubes were of thesame volumetric weight. To form a monolith, part of the moulds filled with sand were placed in water, and the other part in bitumen heated up to 200. C. They were kept there until all the cavities between the grains were filled up by the water and bitumen. The cubes of sand filled with sand and water were placed in a refrigerator and frozen, While thoseimpregnated with bitumen were cooled in the laboratory premises. The frozen cubes and those with the solidified bitumen were taken out of the moulds and tested for compression. The cubes impregnated with bitumen were tested in cool premises and the frozen onesin a room with a temperature b6lOW'O C. In summer, the.

frozen cubes after being taken out of the molds were placed in a refrigerator, from which they were taken out immediately before the compression test. The ice and the solidified bitumen in the samples were regarded as a binder between the grainsof the various kinds of sand, and it was presumed that under the same temperature conditions the, iceand the solidified bitumen in filler. Table 4 presents the results of the tests of the samples in a frozenstate.

It can be seen from the data in Table 4 that all the cube samples made of disintegrated sand had a greater compressive strength than those made of sand ground in a vibration mill. Considering that the strength of such cube samples depends not only on the strength of the sand grains, but also to a great extent on the geometrical shape of the sand grains and on the granulometric composition of the sand,it may still be assumed that the greater strength of the disintegrated sand is due to a certain degree to the strength of the grains themselves after sand-pit Quartz? is 71% (Table 3). Comminuting of 50 grinding.

TABLE 4 Sample Volumetric Temperature Average Specific surweight of sand during com- Maximum compressive Sand face of sand, in cubes, pressive test, compressive strength,

sq. cinJg. g./cu. cm. C. No strength, kgJsq. vcm.

kgJsq. cm.

151 Disintegrated 678 1. 75 157 123 Ground in a vibration mill. 670 1. 75 121 91 Natural 1. 75 93 The results of the following experiments likewise confirm the existence of a better structure in the grains of disintegrated sand in comparison with the sands ground in a ball mill or a vibration mill.

For the smallsized fractions of sand ground in the various machines the granulometric composition was determined by means of sedimentation analysis directly after grinding and after keeping the sand in water for seven days. While the sand was in the water, the fineness of all the sands increased, the growth in the specific surface of disintegrated sand proving to be smaller as compared with sands ground in a ball mill or a vibration mill. It may be assumed that the decomposition of the sand particles took place under the action of water through the surface faults of the grains. The results of the test are given in Table 5.

The frost resistance of sand from the sand-pit of Quartz was determined, the sand being placed in tin receptacles in a natural state and ground in a ball mill, a vibration mill and a disintegrator. The sand in the receptacles was saturated with water and subjected to freezing in a refrigerator. After every freezing the samples were thawed out in water at a temperature of 15 C. The changes in the specific surface of the sand were determined after 10, 15 and 20 freezing-thawing cycles. The

between the blocks is filled up with a glass-like structure, its regularity being less distinct as compared with a crystal structure. The bonds between the ions and atoms of this structure differ and they are less strong than the bonds in an ideal crystal.

Sands of various genesis have a bond spectrum of varying kinds. It is clear that the structure of the sand has a noticeable influence on its grindability. But with a reduction in the size of the particles of the material the number of defective areas gradually drops. This leads to strengthening of the small particles of the material. Strengthening of the material begins after the particles reach a size of 1 to 2 mm. Consequently, this size is the natural boundary between crushing and grinding. Sufliciently small particles attain the maximum strength upon which there are already no faults. It has been established by investigations that this boundary sets in when the size of the particles is about 0. 1 micron.

The highest efiiciency of crushing and grinding is attaned in high-frequency mechanical action, i.e. periodically arising stressed conditions. The weak spots in the structure of material being deformed possess a capacity for selfrestoration and for joining together under the action of the molecular forces of adhesion. This joining can be avoided by using high-frequency act-ion.

With high frequencies all solid materials are destroyed like fragile bodies, requiring a minimum of power for the destruction. As the frequency of vibration increases, the number of fissures which have time to restore them- 0 selves diminishes, thus leading to the destruction of the body in a shorter period and with a smaller consumption of power.

The same kinds of sand ground in various machines have a different structural strength. In the process of grinding, there takes place not only splitting of the grains along the existing faults in the real structure of the material, but simultaneously new faults are also created under the action of mechanical forces. If the acting mechanical forces are weak and the individual impulses are insignificant then results of the tests are given an Table 6.

TABLE 6 Treatment Sand Before After 10 After 15 After 20 freezing freezing freezing freezing cycles cycles cycles Natural sand:

Specific surface, sq. cum/g 73 84 97 106 Structural Strength after freezing, (6/61) 100,

in percent 87 75 69 Ground in a ball mill:

Specific surface, sq. crn./g 282 338 377 478 Structural strength after freezing, (e/a1).100,

in percent 83 75 59 Ground in a vibration mill:

Specific surface, sq. crn./g 267 322 363 454 Structural strength after freezing, (e/e1).100,

in percent 83 74 59 Ground in a desintegrator:

Specific surface, sq. crn./g 312 312 315 328 Structural strength after freezing, (c/c;).100,

in percent 100 99 98 There are a number of considerations regarding the crushing of material. In crushing, new surfaces take place as a result of stresses set up in the material which exceed the maximum elastic deformations.

It is known that solid bodies have weak areas in their crystal lattice, as well as fissures. It is natural that the material is destroyed first of all in these weak areas. The condition of a solid body during crushing depends above all on its real structure. The real structure implies all the typical properties of the fine structure of a solid body. The basis of a fine structure is the lattice of an ideal crystal, for example, atoms of Si and O alternately in SiO The crystal surfaces of all solid bodies longer than 1 micron are composed of so-called mosaic blocks which are cryst-allographically located irregularly in respect to new fissures are formed on the surface layer of the sand being ground and small particles of the material are split off. The existing faults inside the grains also continue to develop. First of all, the fissures of the real structure of the crystal become deeper. The internal faults may develop until the grain splits along the weakest plane, depending on the magnitude of the force and the number of times it is applied. If the intensity of the forces proved to be insufiicient to crush the grains, the structure of the grains may even become worse during grinding and the structural strength of the sand may decrease. Since sand is ground in a vibration mill by means of weak impacts and by abrasion, its structural strength becomes worse.

In a ball mill the material receives a small number of each other, and their size may reach a micron. The space impacts of a medium force. In this case abrasion of the 23 material between the balls is of great importance, which also leads to an increase in the surface faults.

In disintegrators of the present invention the grain of sand strikes the hard surface of a steel member at a velocity of at least m./sec. and prefer-ably 50 to 200 m./sec.,

receiving a strong sharp impact. Such imparts follow eachin the strength of samples of sand ground in various ma chines is due only to the different geometrical shape of the grains, to the granulometric composition and the different structural strength, or whether the sand grains acquire still other properties affecting the strength of the products. To clear up this question an experiment was performed involving the freezing of samples and there was also determined the strength of steamed samples prepared under identical conditions of lime and sand having various size grains, with a content of active CaO 10% and with steaming for three hours under a steam pressure to 8 atm. gauge. The results of the tests of these samples are given in Table 7.

TABLE 7 Grinding machine Disin- Ball Vibration tegrator mill mill Specific surface of sand sq. em./g 500 500 500 Frozen Cubes:

Volumetric weight of dry substance, g./eu. cm 1. 8 1.8 1.8 Compressive strength, kg./sq. cm. 259 226 192 Relative compressive strength,

percent 100 87 74 Volumetric weight, g./eu. em 1. 9 1. 9 1. 9 Steamed Cubes:

Compressive strength, kg.lsq. cm. 741 537 479 Relative compressive strength,

percent 100 72 65 Ratio of compressive strength of steamed and frozen cubes:

Absolute strength 2. 86 2. 38 2.50 Relative strength 1.00 0.83 0. 88

The compressive strength of the frozen and steamed samples is considerably greater for samples made of sand ground in a disintegrator.

It may be presumedfrom the data in Table 7 that all the differences between the tested sands are not only explained by thegreater strength of the disintegrated sand grains and their better shape and granulometric composition.

Sand is the basic material in the manufacture of limesand products. The contents of sand in these products exceed those of lime by from 8 to 10 times. Therefore improvements in the technology of lime-sand products should be aimed, above all at improving the properties of the sand.

Upon mechanical deformation of a solid, part of the work is absorbed by the substance being deformed; similarly during the grinding of sand there also takes place besides the crushing, a process of absorbing a part of the mechanical energy in the material being ground. The amount of energy absorbed depends on the kind of deformation of the solid body, whichhas taken place. Upon compression the absorption of energy is considerably higher than in elongation or bending. It is also known that the change in the crystal lattice of a substance and the amount of energy accumulated is greater for dynamic deformation than for static one.

The amount of energy accumulated grows in proportion;

tion of a new surface, the appearance of microscopic fissures and faults in the crystal lattice. The chemical activity of the substance, its solubility and diffusion properties increase. The chemical activity of the sand, its solubility and diffusion properties play an important part in the formation of the qualitative structure of sand-lime products. The accumulation of energy connected with the formation of a faulty lattice is especially great upon deformation of the material by compression. Therefore, preference should be given tosuch grinding machines that cause the greatest deformation of the material being ground by compression.

The relationship between the strength and the capacity of the material for deformation on one hand and the rate of deformation on the other has been studied adequately enough in the field of metals. During a momentary impact the material withstands considerably greater loads than during a continuous one, and large local permanent deformations are formed. A physical explanation is. the following:

In a lime-sand monolith the sand grain is simultaneously a filler and a component of the binder, Which combines during steaming with the lime and the other sand grains into a strong monolith. As a binder the sand grain should possess the most active surface layer, and the greatest strength as a filler.

In this connection a machine for preparing lime-sand mixtures should reduce the number of faults in the sand grain structure and increase the strength. of the grains by crushing-them along the weakest mosiac surfaces. This can be achieved by subjecting the grains of said to separate strong and frequent impacts. Sand grains in a disintegrator, striking the bars members with a great velocity receive powerful impacts. As a result they are crushed along the weak planes of the structure. Considerable local stresses appear at the points of contact, Whichactivate the sand grains in the surface layer. Deformations of the sand grains at velocities of m./sec. may spread to a depth of over 10 micron or to 5% of the grain diameter. The size of the area of the deformed surface caused by one impact amounts to about 5-10% of the initial surface. In a disintegrator, where each grain of sand receives at least three impacts, the surfaces of even strong and faultless sand grains, not crushed by the impact are ac- .tivated.

In Table No. 8 are reported the specific weights of sandy grinded to a different specific surface by the disintegrator, a vibration mill and a ball mill. It can be immediately seen that for all the values of the specific surface considered the maximum decrease in, the specific weight is shown by the sand processed in the 'disintegrator; such a decrease is a direction of the existence of an activated surface layer deeper than the limited activated layer formed on the surface of sand grinded using ball mills or vibration mills.

Similar results can be obtained measuring other properties of the sand,

When sand and slaked lime are jointly let through a disintegrator, they are also ideally mixed. The air currents and vortexes formed in the disintcgrator carry av thin fine lime dust in a suspended state until it adheres cornpactly to the surface of the. sand grains. The lime is thus initially connected with their freshly formed active surface.

When grinding sand and processing lime-sand products in a disintegrator the all sand grains are under special conditions as compared with those in a ball mill or in a vibration mill. This leads not only to a change in the mechanical and geometrical properties of the sand grains, but also to their higher activity and intimate mixing.-

The relatively weak impacts received by the sand.

grains when ground in a vibration mill are incapable of crushing the large grains of sand. Intensive grinding begins when the grains are of a certain minimum size. Weak impacts in the large grains of sand deepen the fissures in their structure and reduce their structural strength.

In a ball mill, where the diameter of the sand grains is infinitely small in comparison with that of the balls, the sand during grinding occupies mainly the space between the balls. The larger grains are subjected to intensive impacts, and during prolonged grinding the granulometric composition becomes uniform. Here the force of the impacts is likewise small and for this reason there is an increase in the faults in the sand grains and a reduction in their structural strength.

It will be apparent that many changes and modifications of the several described herein may be made without departing from the spirit and scope of the invention. It is therefore apparent that the foregoing description is by way of illustration of the invention rather than limitation of the invention.

What is claimed is:

1. A method for treating particulate material each particle having a size of from .2 microns to less than 2 inches in a major dimension comprising introducing said material into the center of an impact zone, hurling said particles at a velocity of at least meters per second, successively impacting said hurling particles at least three times whereby their course of travel is changed and said successive impacts are carried out within 0.05 second of each other and thereafter removing said particulate ma.- terial from said impact zone.

2. A method for treating a particulate material selected from the group consisting of sand, ores, cinders, ashes, loess, pozzolan silicalcite chips, cement clinker, lime and corn, each particle having a size of from .2 microns to less than 2 inches in a major dimension comprising introducing said material into the center of an impact zone, hurling said particles at a velocity of at least 15 meters per second, successively impacting said hurling particles at least three times whereby their course of travel is changed and said successive impacts are carried out Within 0.05 second of each other and thereafter removing said particulate material from said impact zone.

3. A method for treating sand particles each particle having a size of from .2 microns to less than 2 inches in a major dimension comprising introducing said sand particles into the center of an impact zone, hurling said sand particles at a velocity of at least 15 meters per second, successively impacting said hurling sand particles at least three times whereby their course of travel is changed and said successive impacts are carried out within 0.05 second of each other and thereafter removing said sand particulate material from said impact zone.

4. A method for treating ores particles each particle having a size of from .2 microns to less than 2 inches in a major dimension comprising introducing said ores particles into the center of an impact zone, hurling said ores particles at a velocity of at least 15 meters per second, successively impacting said hurling ores particles at least three times whereby their course of travel is changed and said successive impacts are carried out within 0.05

26 second of each other and thereafter removing said ores particulate material from said impact zone.

5. A method for treating cinders particles each particle having a size of from .2 microns to less than 2 inches in a major dimension comprising introducing said cinders particles into the center of an impact zone, hurling said cinders particles at a velocity of at least 15 meters persecond, successively impacting said hurling cinders particles at least three times whereby their course of travel is changed and said successive impacts are carried out within 0.05 second of each other and thereafter removing said cinders particulate material from said impact zone.

6. A method for treating ashes particles each particle having a size of from .2 microns to less than 2 inches in a major dimension comprising introducing said ashes particles into the center of an impact zone, hurling said ashes particles at a velocity of at least 15 meters per second, successively impacting said hurling ashes particles at least three times whereby their course of travel is changed and said successive impacts are carried out within 0.05 seconds of each other and thereafter removing said ashes particulate material from said impact zone.

7. A method for treating loess particles each particle having a size of from .2 microns to less than 2 inches in a major dimension comprising introducing said loess particles into the center of an impact zone, hurling said loess particles at a velocity of at least 15 meters per second, successively impacting said hurling loess particles at least three times whereby their course of travel is changed and said successive impacts are carried out withing 0.05 second of each other and thereafter removing said loess particulate material from said impact zone.

8. A method for treating pozzolan particles each particle having a size of from .2 microns to less than 2 inches in a major dimension comprising introducing said pozzolan particles into the center of an impact zone, hurling said pozzolan particles at a velocity of at least 15 meters per second, successively impacting said hurling pozzolan particles at least three times whereby their course of travel is changed and said successive impacts are carried out within 0.05 second of each other and thereafter removing said pozzolan particulate material from said impact zone.

9. A method for treating silicalcite chips particles each particle having a size of from .2 micron to less than 2 inches in a major dimension comprising introducing said silicalcite chips particles into the center of an impact zone, hurling said silicalcite chips particles at a velocity of at least 15 meters per second, successively impacting said hurling silicalcite chips particles at least three times whereby their course of travel is changed and said successive impacts are carried out within 0.05 second of each other and thereafter removing said silicalcite chips particulate material from said impact zone.

10. A method for treating cement clinker particles each particle having a size of from .2 micron to less than 2 inches in a major dimension comprising introducing said cement clinker particles into the center of an impact zone, hurling said cement clinker particles at a velocity of at least 15 meters per second, successively impacting said hurling cement clinker particles at least three times whereby their course of travel is changed and said successive impacts are carried out Within 0.05 second of each other and thereafter removing said cement clinker particulate material from said impact zone.

11. A method for treating lime particles each particle having a size of from .2 micron to less than 2 inches in a major dimension comprising introducing said lime particles into the center of an impact zone, hurling said lime particles at a velocity of at least 15 meters per second, successively impacting said hurling lime particles at least three times whereby their course of travel is changed and said successive impacts are carried out within 0.05 sec 0nd of each other and thereafter removing said lime particulate material from said impact zone.

Claims (1)

1. 22. A METHOD FOR TREATING AT LEAST TWO TYPES OF PARTICULATE MATERIAL TOGETHER, THE PARTICLES OF ONE TYPE BEING PREFERABLY IN THE FORM OF A POWDER, THE PARTICLES OF THE SECOND TYPE BEING LARGER THAN POWDER AND FROM .2 MICRONS UP TO 2 INCHES IN A MAJOR DIMENSION COMPRISING INTRODUCING BOTH TYPES OF SAID PARTICULATE MATERIAL INTO THE CENTER OF AN IMPACT ZONE, SIMULTANEOUSLY INTRODUCING WATER INTO SAID IMPACT ZONE, HURLING SAID PARTICLES OF SAID SECOND TYPE AT A VELOCITY OF AT LEAST 15 METERS PER SECOND, SUCCESSIVELY IMPACTING SAID HURLING PARTICLES OF SAID SECOND TYPE AT LEAST THREE TIMES WHEREBY THEIR COURSE OF TRAVEL IS CHANGED AND SAID SUCCESSIVE IMPACTS ARE CARRIED OUT WITHIN 0.05 SECOND OF EACH OTHER, AT THE SAME TIME COATING SAID PARTICLES OF THE SECOND TYPE WITH THE PARTICLES OF SAID FIRST TYPE THEREAFTER REMOVING SAID PARTICULATE MATERIAL FROM SAID IMPACT ZONE, THEN COMPACTING SAID TREATED MATE-

Images