US1359094A - Process of making decolorizing carbons - Google Patents

Description

, UNITED STATES l Ararrr -oF 1cE-,.

RUSSELLWIiIiIAM 'MuMFORD, or NEW YORK, N. Y., assmNon'ronnrimuq rnonuc'rs ooaronarron, or WILMINGTON, DELAWARE, A coReoRArIo'N' OF DELAWARE.

No Drawing.

To all whom it may concern Be it known that I, RUSSELL WILLIAM MUMFORD, a citizen of the United States,

. powders .a very finely pulverulent state beof,their fineness, they often rather contrib New residin at New York, in the county of ork and State of New York, have invented certain 'new and useful Improvements in Processes of makingpecolorizing Carbons, of which the following is a specification. s y

This invention relates to processes of making decolorizing carbons; and it comprises a method, of making decolorizing carbon wherein finely powderedcoal, lignite or brown coal is admixed withvarious agents, such as milk of lime and phosphate solution, ammoniacal tar, etc. together with, usually, a mineral spacing agent, such as dolomite, and is gradually. heated through.

a wide ran e of temperatures extending above 600 all as more fully hereinafter set forth and as claimed.

Decolorizing carbon is the commercial name now given'to certain carbon-preparations made from vegetable materials and: distinguished from charcoal and thelike, by a high-power of decoloriz'ing liquids such as sugar solutions. These Idecolorizing carbons are .even more active intheir adsorbing and decolorizing power than is boneblack and can beused for many purposes for which boneblack is not suitable. For the most part, they occur as very fine ing considered necessary to give a large area of surface; the large surface upon which their high'degree of activity, at least in part, depends While'they are eflicient in removing color from sugar solutions, oils and the'like, they are not active in removing fine suspended solids; and they do not give bright or clear solutions." In fact, because ute to the turbidity, some portion of the carbon remainingm suspension and form-1 ing a blackishcloud. In the use of decolorizing carbons it is therefore common to follow them with a clarifying agent having the power of removing suspended solids, suchas kieselguhr. In another application, Serial No. 167,971 filed Mayv 11, 1917 (Patent No. 1,286,187, Nov. 26, 1918,) I have described and claimed a method of making decolorizing carbons which not only have a high activity as regards decolorization but are rioo d ginning at 250 PROCESS or'M -Kms nncoLoRizmG cannons.

also active in removing suspendedisolids; that is they not only have a decolori'zing .action'but also a clarifying action. Briefly Specification of Letters Patent. L Patented Nov, 16, 1920. Application filed March 23, 1918. Serial No. 224,199. I

stated, this method comprises making a- I mixture of a vegetable material, such as sawdust or peat, with various colloids and charring the mixture slowly through of temperatures endin v p In charring any vegeta 'le matter the first effect is the production of various tars, gases,'vapors, etc.. These prod- -ucts in their turn carbonize withthe separation of more carbon. The carbon coming above directly from the vegetable materialmay be called primar'y carbon and that formed by heating the volatile'products may be called secondarycarbon. With any quick heating action the secondary carbon tends to form in the pores of the primary carbon and clog them. This is" very undesirable. By the slow heating in the invention of said prior application -I afford time for the volatile products to escape from the pores of the primary carbon, thereby securing an unclogged, highly effective material. In order to aid in securing this result, I ordinarily matter with amineral powder ofsome" char- 0 space apart the particles of'the vegetable acter. TI may use a calcareous material limestone 'or mixture of carbonates of mag? dioxid vat relativel i The magnesium carbonate first loses CO and then the calcium carbonate, 'sothere is a slow and continuous charring but it is itself adsorbed in 't e char to a greater or less extent and as the tem- 'perature goes up it" has a chemical and probably'also mechanical influence on the carbon, It'tends to keep the pores free and to clean,.a1id probably, to some extent at leastg to'widen them somewhat. After they Chair is complete the mineral matter may be removed in var ous way This carbon 'dioxid not onlyv "known as dolomite which is 'a magnesian" nesia and lime and which evolves carbon low temperatures, 'be- S q Y y I explained in Patent No. 1,286,187 that as a' -rule I found it better not to have the raw material fromwhich the carbon is made- Itoo solid or compact instructure, and

that I-usuallypreferred to use materials which are porous. enough 'to have the duced in gas works, and then char I obtain prefer the use of ammoniacal tar.

power pf absorbing water in a substantial amount. I have found, however, that a very efficient type of decolorizing carbon can be made of carboniferous materials of more or less compact structure such as lignite, brown coal, or any other coal or coaly'material high in volatile matter, by mixing them in a powdered condition with a tarry liquid or tarry matters, such as the residues of tar distillation (pitch) to which advantageously ammoniacal liquor may be added. I have found that if I mix coal, brown coal or lignite, which should be reduced to a fine powder of, say, 80 to 150 mesh, with ammoniacal tar, such as is proa material which is highly efficient as a decolorizing and clarifying agent. The. crude tar from the gas works, which always contains more or less ammonia, may be used; or tarry ammonia water may be employed. In either event the coal or lignite powder is made into a dough-like mass with the tar or tarry water, formed into pellets or thelike, and heated 'slowly through a range of temperatures ending above 600 C. In some cases I may mix. the powdered brown coalwith'milk of lime or a mixture of milk of lime and solution of. monocalcium phosphate and'char in the same way; but in the present inventigii I mmoniacal tar may also be used in connection with the other materials. A useful mixture may be made as a dough-like composition of powdered coaly matter and ammoniacal tarry matter with a watery solution of milk of lime and monocalcium phosphate. spacing agent, which is advantageously dolomite, may be mixed in with the other materials prior to forming the dough.

Other tarry materials than gas tar. such as the residues of tar distillation and-similar products, or such as asphaltic materials, may be mlxed with the coal," but I findammoniacal tar to be the best material.

The charring may be performed in any sultable type ofventer retort by any 'suitable method of heating. In order to'sweep out the volatile products formed in charring, currents of steam or products of combustion may be blown through the retort. In one advantageous method of charring whlch I sometimes employ, (see my Patent I No. 1,287,592) I may place the mass-to be charred in shallow covered'tra s and pass them-i 'through atubf1' her heated what A certain proportion of mineral ignition and then the mineral m'atter, if

such be used, may be removed by sedimentation and acids if desired. The carbon is then dried. I find it advantageous to perform the drying in a rotary tube by the waste gases from the firing means used in charring.

In a specific embodiment of the present invention I take brown coal of any suitable kind and grind it to about 80 mesh. The comminuted brown coal I mix with about 5 to 30 per cent. of finely powdered d'olomite and convert the mixture into a doughlike plastic mass with wet ammoniacal gas tar, using the amount of tar which may be necessary to give the desired consistency. The mass is next formed into pellets and placed in a vented retort. A current of dry steam is passed through the retort and the heat is slowly raised until it finally reaches 600 C. or higher. Finishing at a very high temperature is necessary in order to insure as far as practicable the charring of any-- of two kinds of carbon, one coming from the coal and the other from thetarry 'materials. The resultant product also contains more nitrogen than would the coal charred alone. tion in which this nitrogen exists is not known. 7 For some reason the presence of Thecondition or form of combinathis nitrogen in the product is advanta geous to its decolorizing properties.

What I claim is: J

1. The process of making a decolorizing carbon which comprises comminuting coaly matter high in volatile constituents, mixing with tar and ammonia and charring through a range of temperatures slowly rising to above 600 C,

. 2. The process of producing decolorizing whe rhi .e r sssee e afl e L l... 14 or Aid A 1.

a i a r o L Mi" sa es arse oi t carbon which comprises making a doughlike mixture of powdered coaly matter with ammoniacal tarry liquid from gas works and charring the same in a vented retort' through which a draft current of dry steam is passed to facilitate the removal of vapors and continuing the heating through a range of temperatures slowly rising above 600 C.

4. The process of producing decolorizing carbon which comprises making a doughlike mixture of powdered coaly matter and the residues of tar distillation with ammoniacal liquor, and charring the same in a vented retort through which a draft current of dry steam is passed to facilitate the removal of vapors and continuing the heating through a ran e of temperatures slowly rising above 600 6.

5. The process of producing decolorizing carbon which comprises making a doughlike mixture of powdered coaly matter and tarry matter with ammoniacal liquor and charring the same in a vented retort through which a current of dry steam is passed to facilitate removal of vapors, and continuing the heating through a range of temperatures slowly rising above 600 C 6. The process of producing decolorizing carbon which comprlses comminuting coaly matter high in volatile constituents, mixing with tar and ammonia and a mineral powder and charring through a range of temperatures slowly rising to above 600 C.

7. The process of producing decolorizing carbon which comprises making a mixtureof powdered coaly matter and'tarry matter containing ammonia with calcareous matter and charring same through a range of temperatures slowly rising to above 600 (j.

8. The process of producing decolorizing carbon which comprises making a doughlike mixture of powdered coaly matter and ammoniacal tarry matter with a watery solution of milk of lime and monocalcium phosphate, charring the mixture in a vented retort, through which a current of dry steam is passed to facilitate removal of vapors, continuing the heating through a range of temperatures slowly rising above 600 0., and cooling the finished product by passing a current of steam through the retort.

In testimony whereof I aflix my signature h ereto.

RUSSELL WILLIAM MUMFORD.