Method of production of mullite out of the quartz-topaz raw materials
FIELD: chemical industry; methods of production of mullite out of the quartz-topaz raw materials.
SUBSTANCE: the invention is pertaining to the field of a chemical industry, chemical technology and materials technology. The method of production of mullite includes: comminution of the source quartz-topaz raw materials; separation of impurities by lixiviation using treatment of the raw materials with a hydrochloric acid with concentration of 10-38 % within 0.5-2 hours; a water flushing; separation of redundant silicon oxide in the form of ammonium hexafluorosilicate by means of ammonium bifluoride; calcination of the gained product at the temperature of 1200°-1300°C. The technical result of the invention is production of the microfibrous mullite (microfibers of the mullite crystal may reach 200 microns in length with a fiber depth - about 1 micron) of high quality and in the commercial scale.
EFFECT: the invention ensures production of the microfibrous mullite (microfibers of the mullite crystal may reach 200 microns in length with a fiber depth - about 1 micron) of high quality and in the commercial scale.
The invention relates to the field of chemical technology, technology of silicates and can be used to obtain ceramic materials on the basis of mullite.
A known method of producing mullite-based sintering a mixture of silicon oxide and aluminum oxide in a ratio of SiO2·Al2O3=3:2 at a temperature of 1200°C. In the reaction mixture of oxides turns into a needle-like crystals of mullite ["New ceramics", Ed. by UNO, M., 1969]. The disadvantage of this method is the impossibility of an ideal mixture of two solids.
A known method of producing mullite by heat treatment of a mixture of oxides and/or hydroxides of aluminum and silicon, characterized in that, to simplify the method and improve the quality of the target product, the mixture before heat treatment is subjected to mechanochemical activation by its processing in a planetary mill with energonapryazhennosti 3-150 W/g for 0.1 to 3 hours, and the heat treatment is carried out at a temperature of 1150-1300°for 4-20 h [RF Patent №1213679 from 27.09.99,]. The disadvantage of this method is the high cost and lack of efficiency of mechanical activation of the equipment.
A known method of producing mullite of Topaz concentrate, selected as a prototype. The inventive use of the mixture composition, wt.%: alumina 7,7-18,3; cu is masem 37,1-38,5; aluminum fluoride 44,5-55,8. The method of producing crystals of mullite includes loading the crucible mixture containing these components, and heating at 1120-1250°C in an atmosphere of silicon tetrafluoride at a pressure of 0.05-0.2 MPa. Heat the lead for 6-18 h [RF Patent №2056464 from 20.03.1996,]. The disadvantage of the prototype method is the necessity of using aluminum fluoride. The result that stands out toxic gas tetraploid silicon, which requires separate disposal operations.
The present invention is the development of industrial technology for production of mullite from natural quartz-Topaz raw materials.
This object is achieved in that a method of producing mullite includes the operations branch of the original ore impurities of iron compounds and excess silicon oxide and calcining the resulting mixture 3Al2O3·2SiO2to the state of mullite. According to the invention developed the following sequence of operations that allow the separation of valuable components of the ore:
1. Crushed to a particle size 0,074-0.4 mm quartz Topaz concentrate is treated with a hydrochloric acid concentration of 10-38%, for 0.5-2 hours.
2. After leaching of impurities quartz-Topaz concentrate is washed with plenty of water method of decanting.
3. Washed from premise the quartz-Topaz concentrate sitout with biperiden ammonium. 1 kg of quartz-Topaz concentrate consumed 1.5-1.8 kg of byflorida ammonium.
4. The mixture is heated to a temperature of 350°-600°C. When this occurs, obestsenivaya - freeze compartment formed by chemical reaction of ammonium hexafluorosilicate. The total mass of the mixture is reduced to 6.5-7 times. In the result of the operation of obestsenivaya obtained artificial Topaz.
5. Received Topaz calcined at a temperature of 1200°-1300°C. When the calcination is obtained microfiber mullite, the length of the crystal is 200 μm, a thickness of about 1 micron.
The set of features of the proposed method of producing mullite provides:
1. The simplicity of the process, the possibility of organizing a large-tonnage production.
2. The high quality of the resulting product, microfiber crystals of mullite reach a length of 200 μm, the thickness of the fiber is about 1 micron.
In a portion of the quartz-Topaz concentrate 1 kg add 0.5 kg of hydrochloric acid (concentration of hydrogen chloride 36%) and incubated for 2 hours. After leaching of impurities quartz-Topaz concentrate is washed with water and decanted.
Refined quartz-Topaz concentrate sitout with biperiden ammonium. 1 kg of quartz-Topaz concentrate consumed 1.8 kg of byflorida ammonium. The mixture is heated to the fact the temperature 600° C for 10 hours. The mixture at temperatures above 120°transformed into a liquid phase, with further heating hardens at temperatures above 320°With rapid allocation of ammonium hexafluorosilicate, when reaching 600°With the reacted mixture is a powder with a bulk density of 0.25-0.3 g/cm3.
The resulting powder is obesity Topaz with a content of about 10% fluorine. When heated received Topaz up to 1200°he is transformed into mullite. The transition Topaz in mullite is accompanied by release of gaseous hydrogen fluoride and silicon tetrafluoride.
The method of producing mullite from quartz-Topaz raw materials, including the annealing mixture, wherein the pre-quartz-Topaz raw materials are crushed, then treated with hydrochloric acid in a concentration of 10-38% for 0.5-2 h, washed with water, sitout with biperiden ammonium and the mixture is heated to a temperature of 350-600°C, calcined at a temperature of 1200-1300°C.
SUBSTANCE: invention relates to manufacture of molded ceramic materials for use as propping agent in production of liquid and gaseous fluids from bored wells. Method comprises briquetting and heat treatment of aluminosilicates kaolin at 1150-1250оС. Resulting mix is ground to average grain size 3-5 μm and loaded into granulator. Before granulation, 1.2-3.0% mineralizer and 5-10% plasticizer are added. Mix is moistened with dozed amount of organic binder and stirred to form granules. At the end of granulation, fired ground material for powdering granules is added in amount 1.2-3.0%. Granules are dried and screened to isolate desired fraction, which is subjected to final firing at 1370-1450оС for 30-60 min and then re-screened into commercial fractions.
EFFECT: enabled manufacture of granules having low loose density and high strength allowing their use at depths up to 14000 feet (4200 m).
3 cl, 1 dwg, 1 tbl, 3 ex