Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
  • C01F7/00—Compounds of aluminium
  • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
  • C01F7/20—Preparation of aluminium oxide or hydroxide from aluminous ores using acids or salts
  • C01F7/22—Preparation of aluminium oxide or hydroxide from aluminous ores using acids or salts with halides or halogen acids
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
  • C01F7/00—Compounds of aluminium
  • C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
  • C01F7/30—Preparation of aluminium oxide or hydroxide by thermal decomposition or by hydrolysis or oxidation of aluminium compounds
  • C01F7/306—Thermal decomposition of hydrated chlorides, e.g. of aluminium trichloride hexahydrate
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
  • C01F7/00—Compounds of aluminium
  • C01F7/48—Halides, with or without other cations besides aluminium
  • C01F7/56—Chlorides
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B21/00—Obtaining aluminium
  • C22B21/0015—Obtaining aluminium by wet processes
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
  • C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
  • C22B3/06—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions
  • C22B3/10—Hydrochloric acid, other halogenated acids or salts thereof
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/80—Compositional purity

Definitions

• the invention relates to metallurgy, in particular to acidic methods for producing alumina and can be used in the processing of low-grade aluminum-containing raw materials.
• a known method of producing alumina from high-silica bauxite through hydrochloric acid leaching including roasting aluminum-containing raw materials at temperatures up to 700 ° C, treating it with hydrochloric acid, salting out aluminum chloride by saturating the clarified chloride solution with hydrogen chloride gas, calcining aluminum chloride to obtain aluminum oxide and pyrohydrolysis with the return of hydrogen chloride at the stage of acid treatment and salting out (Eisner D., Jenkins DH and Sinha HN Alumina via hydrochloric acid leaching of high silica bauxites - process development. Light metals, 1984, p. 411-426).
• the disadvantages of this method should also include the need to obtain dry gaseous hydrogen chloride at subsequent stages of the technology to return it to the redistribution of salting out, which in some cases complicates the process and increases the consumption of thermal energy.
• the basis of the invention is the task of developing a method for producing metallurgical alumina from low-grade raw materials, which allows processing of poor high-siliceous ores and waste.
• the technical result is to increase the quality of alumina and reduce energy consumption.
• the method of producing alumina is as follows.
• a clarified solution of aluminum chloride after leaching of natural aluminum-containing raw materials with hydrochloric acid, separation of insoluble precipitate and preliminary evaporation to a saturation stage with a concentration of about 30% according to A1Cl 3 is mixed with a 50-70% CaCl 2 solution (700-900 g / l), based on further reducing its concentration in a mixed solution below 30-40%. Crystallization is carried out in the presence of seed crystals of aluminum chloride hexahydrate with a particle size of 250-500 microns, continuing evaporation and maintaining the rate of salt evolution, providing the required size of production crystals.
• the crystallization process is completed after increasing the concentration of CaCl 2 in the mother liquor to the initial level of 700-900 g / l and reducing the content of Al 2 0 3 to 5-10 g / l. At the same time, more than 90% of A1 2 0 3 entering the process is released with salt. The resulting pulp is separated, the mother liquor is returned to the head of the process, and the crystals of aluminum chloride hexahydrate are sent to obtain alumina by thermal decomposition.
• a method for producing alumina is illustrated by specific examples.
• the clarified chloride solution was evaporated in a flask to an AlCl content of 3 31% and gradually poured into heated 60 percent calcium chloride solution prior to isolating the crystals of aluminum chloride hexahydrate was added and seed crystals of a size of 250-500 microns from previous experiments in an amount equal to twice the calculated weight A1C1 3 -6H 2 O introduced into the process with chloride clarified pa create, continuing evaporation for 1 hour.
• the resulting crystals were washed with 38 percent hydrochloric acid on the filter, and calcined at 1000 ° C.
• the content of P 2 O 5 in the obtained alumina was less than 0.001%, and the average particle size of the product was 82.3 ⁇ m. This fully meets the requirements for metallurgical alumina.
• Example 2 The experiment was repeated under the same conditions, but without introducing calcium chloride into the process.
• the content of P 2 O 5 in the obtained alumina was 0.004%, and the average particle size of the product was 71.2 ⁇ m, that is, there is a mismatch with the requirements for the content of impurities.
• Example 3 The experiment was repeated under the conditions of Example 1, but crystals of aluminum chloride hexahydrate of size 100-250 ⁇ m were introduced as seeds.
• the content of P 2 O 5 in the obtained alumina was less than 0.002%, and the average particle size of the product was 52.2 ⁇ m, that is, there are inconsistencies with the requirements for particle size distribution.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Inorganic Chemistry (AREA)
• Thermal Sciences (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Materials Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Environmental & Geological Engineering (AREA)
• Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)

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• 2012
  • 2012-08-01 WO PCT/RU2012/000630 patent/WO2014021729A1/ru not_active Ceased
  • 2012-08-01 CN CN201280074926.4A patent/CN104736482B/zh not_active Expired - Fee Related
  • 2012-08-01 IN IN662DEN2015 patent/IN2015DN00662A/en unknown
  • 2012-08-01 CA CA2877653A patent/CA2877653C/en not_active Expired - Fee Related
  • 2012-08-01 US US14/417,724 patent/US9322080B2/en not_active Expired - Fee Related
  • 2012-08-01 AU AU2012386620A patent/AU2012386620B2/en not_active Ceased
  • 2012-08-01 RU RU2013151914/05A patent/RU2570077C2/ru not_active IP Right Cessation

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