What are the barite beneficiation methods?
The choice of barite beneficiation method is influenced by the type of ore, the nature of the ore, the size of the mine, and the use. The main mineral processing methods currently used are shown in the table. Generally, the residual ore is easy to be selected. Therefore, the re-election method is preferred; the sedimentary ore and the hydrothermal ore associated with sulfide ore, fluorite, etc., in addition to re-election, flotation method; barite flotation Anionic collectors generally used: fatty acid salts, petroleum sulfonates or sulfates.
The beneficiation process of residual barite ore is mainly selected by re-election method, that is, after washing, crushing, sieving, quartet concentrate is selected by jigging or other re-election method. .
The method of ore dressing for barite
Hand separation: After the original ore is mined, simple manual selection is the method of mineral processing commonly used in many small mining sites. Some mines, due to high geological grades and stable quality, can meet export requirements after hand selection. For example, the Pancun Mine in Xiangzhou, Guangxi, selects the rich ore by hand selection. The particle size requirement is 30-150mm, BaSO4>95%, and generally can be greater than 92%. The hand selection method is simple and easy, and does not require any equipment, but the productivity is low and the resources are wasted.
Gravity separation: The original ore is washed, screened, crushed, graded and de-sludged. After the jigging process, fine concentrates with good quality can be obtained, and the product grade can reach over 88%. The crusher generally uses a jaw crusher or an impact crusher, and the fine crusher generally uses a pair of roller crushers. Select heavy medium drum sorting machine, cone classifier, jig sorter or shaker, screw machine, etc. The barite inlay has a particle size greater than 2 mm, and can usually be sorted by a heavy medium and jigging. The maximum particle size for heavy media separation is 50mm, and the maximum particle size for wet and dry jigging is about 20mm. The inlaid particle size is less than 2 mm and can be sorted by a shaker or a spiral classifier. Before the selection, a hydrocyclone should be used to remove the mud to improve the sorting effect.
: It is commonly used to select some iron-containing minerals such as siderite, which are used for barite raw materials that require very low iron-containing bismuth-based drugs.
: Flotation must be used for the sorting of ore and re-selected tailings with very fine grain size. There are two kinds of flotation, positive flotation and reverse flotation. Reverse flotation is usually to remove alkali metal sulfide.
As a common salt mineral, barite is divided into two types according to the adsorption form. One is an anionic collector such as fatty acid alkyl sulfate or alkyl sulfonate, which is in the form of chemical adsorption. It is adsorbed on the surface of the barite mineral and separated from the other; the other is the flotation of barite in the form of physical adsorption using a cationic amine collector. Amine collectors are low in efficiency and sensitive to slime, so anionic collectors are preferred. Usually, NaOH is added to the ball mill to adjust the pH value to 8 to 10. The water glass is added to the slurry as a conditioning agent, and the oleic acid collector is used for flotation under the condition of a solid concentration of 40% to 50%.
Processing of barite powder
1. Processing of high whiteness fine powder and ultrafine powder
The whiteness finely pulverized barite powder is obtained by pulverizing, washing and whitening the barite ore. The powder maintains the crystal structure of minerals and is widely used in coatings, rubber, plastics, paper, ceramics and other industries. It is a high-quality filler.
The Suizhou barite deposit is a sedimentary layered deposit. The results of mineral chemical analysis are: BaSO4 94.78%, acid soluble 2.1%, Si 0.72%, organic carbon 0.56%, Ca 0.43%, Fe 0.12%, Al 0.10%, Mg 0.17%. After several times of crushing, the ore is micron-sized fine raw material, which is calcined in a roaster for 2.5 hours to become clinker. After washing with water to remove alkali, it is beaten with dilute acid and then added with sulfuric acid and aluminum powder (acid solution, Bleaching, stirring reaction at boiling temperature for 2.5 h, to obtain a bleaching material, washing off the soluble salts with water, pressing and drying (170 ° C) to become a finished product. The technical performance of the product meets the quality specifications of IS03262 barite b grade.
The chemical reaction process of acid reduction in the reactor is as follows:
Acid solution: dissolves impurities and colored elements with sulfuric acid. [Fe2O3]+3H2SO4=Fe2(SO4)3+3H2O [MnO]+H2SO4=MnSO4+H2O [NiO]+H2SO4=NiSO4+H2O
Bleaching: Adding aluminum powder, generating hydrogen, reducing Fe2+ to bleach. 2Al+3H2SO4=Al2(SO4)3+3H2 Fe2(SO4)3+H2=2FeSO4+H2SO4
Among the above physical and chemical processing methods, bleaching treatment and ultrafine grinding are two key technologies. The bleaching treatment is carried out by calcination (removing carbon) and pickling (removing impurities and colored elements). Therefore, it is necessary to grasp the calcination temperature and time, the acid concentration, the rinsing time, the amount of the reducing agent added, and the number of times of addition and release, etc., which should be reasonably selected. Ultra-fine grinding should use high-efficiency grinding machine and reasonable selection of relevant parameters.
2. Production of strontium salt products
Barium salt products are produced from barite as raw material. In addition to lithopone (zinc bismuth white), it is mainly barium carbonate, barium chloride, barium hydroxide, barium nitrate, barium sulfate, barium titanate, barium molybdate and some fine Chemicals.
(1) Lithopone (zinc bismuth white) is a white powder with an average particle size of 0.3 to 0.5 μm. It is insoluble in water and does not work with hydrogen sulfide and lye. It decomposes in acid solution to release hydrogen sulfide. It will change color after long-term sun exposure, but it can still restore the original color when placed in a dark place. In addition to barite, the raw materials for the production of lithopone are zinc oxide, sulfuric acid, pulverized coal, etc. The main chemical reactions are: ZnO+H2SO4=ZnSO4+H2O BaSO4+2C=BaS+2CO2 ZnSO4+BaS=ZnS·BaSO4
(2) The main raw materials of barium carbonate are barite, limestone and coal. The process flow is: barite, pulverized coal → pulverization → roasting → heating steam leaching → clarification → carbonization → adding soda ash, steam desulfurization washing → filtration → drying → packaging.
(3) Barium chloride barium chloride is a white shiny monoclinic crystal which loses water when heated to 113 ° C and becomes a white powder. Soluble in water, solubility increases with increasing temperature. The aqueous solution has a bitter and salty taste and is toxic to humans, animals and insects.
The main raw materials are barite, coal, hydrochloric acid or chlorine, calcium chloride and the like. The preparation method includes a hydrochloric acid method, a calcium chloride method, and a chlorination method. The hydrochloric acid method, the barite and the pulverized coal are calcined and reacted with hydrochloric acid to obtain. The calcium chloride method is also firstly reduced and calcined, and then obtained by leaching, desulfurization and the like. The chlorination method is a method in which a ruthenium sulfide solution is reacted with chlorine gas to obtain a ruthenium chloride solution, which is then treated.
(4) Barium hydroxide barium hydroxide is a white tetragonal system, soluble in hot water, and the solution is strongly alkaline. Anhydrous cesium hydroxide is a glossy white amorphous powder that is toxic.
In industrial production, the caustic soda method is mainly used, that is, it is obtained by reacting caustic soda with barium chloride solution, and evaporating, crystallizing and separating. The main chemical reaction: BaCl2+2NaOH→Ba(OH)2+2NaCl
(5) Neodymium nitrate is a colorless or white cubic crystal, soluble in water and concentrated sulfuric acid. It decomposes at high temperature and decomposes into oxide when burned to emit green light and is toxic. It is mainly made of concentrated nitric acid and barium carbonate, and is also made of nitric acid (50%) and barium sulfide. The first grade product contains lanthanum nitrate ≥99.0%, and the second grade product ≥98.5%. (6) Precipitated barium sulfate (barium sulfate) Barium sulfate is a white crystalline powder which is hardly soluble in water and is fused to fuming sulfuric acid and molten alkali. It is easy to mix with potassium permanganate, calcium carbonate or alkali metal nitrate. It can be reduced to strontium sulfide by co-heating with carbon.
The production method includes barite refining method and Glauber's salt-sulfurization method. The former is calcined with barite and coal powder, and then reacted with Na2SO4. The latter is reacted with barium sulfide and thenardite, and is subjected to pressure filtration and drying. Made separately.