I. Related overview 1. Theoretical composition %: BaO 65.7, SO3 34.3, often containing Sr, Ca, Pb. Ba and Sr can be replaced by completely homogeneous images. 2, physical properties: pure is colorless and transparent. Generally white, gray, light yellow, light brown; containing impurities can be light blue, pink, gray dark and so on. The streak is white. Glass luster, cleavage surface pearl luster. Hardness 3~3.5. Crisp. The relative density is 4.3~4.5. With low wear and good shielding, it can absorb X-rays and r-rays. 3, the combination of production: mainly produced in low temperature hydrothermal veins, such as quartz - barite , fluorite - barite. 4, industrial applications ⑴ chemicals: for extracting metal barium and a barium compound was prepared. (2) Drilling mud raw materials: Barite is soft, dense, chemically inert, and most of its output is used as a drilling mud weighting agent. (3) Chemical filler: Barite powder is a general industrial filler and a good brightener and weighting agent. (4) Medical aspects: Barite has good absorption of X-rays and r-rays, and thus can be used as a shielding material for the diagnosis of X-ray angiography. Second, the type of deposit China's barite deposits can be divided into four types, namely sedimentary deposits, volcanic sedimentary deposits, hydrothermal deposits and residual slope deposits. Distribution of minerals: Barite resources are abundant in the world, mainly distributed in the United States, the Soviet Union, China, Peru, India and other countries, the world's barite reserves are 2 billion tons. China's barite is rich in resources. It is distributed in 26 provinces and municipalities across the country, mainly in the south. Guizhou Province accounts for one-third of the country's total reserves. Hunan and Guangxi rank second and third respectively in China. The stone not only has a large reserve, but also has a high grade, BaSO4>92.8%. The rich ore reserves accounted for 99.4% of the country's total rich ore, and the large and medium-sized mines accounted for 88.4% of the national total. By the end of 1995, China had proven reserves of 460 million tons of barite. Third, the main industrial indicators of the deposit Boundary grade: barium sulfate (BaSO4) 10% Industrial grade: barium sulfate (BaSO4) 30% Available thickness: 0.25 m for the primary deposit and 1 m for the weathered clay deposit. Fourth, the nature of the ore Ore mineral composition (Table 1) Table 1 Types and characteristics of ore of barite Ore type mine stone special point Major minerals and associated minerals Sedimentary type Block or stripe and bean grain structure Barite, quartz, clay minerals, pyrite, etc. Hydrothermal type Dense, gray to white Barite, pyrite, copper ore, galena, sphalerite, hematite, fluorite, etc. witherite Volcanic sedimentary type Barite, siderite, mirror iron ore, etc. Residual slope type Easy to choose, high grade Barite, fluorite, calcite , quartz, etc. The mineral characteristics of barite minerals are the most common barium-rich minerals. Their properties are listed in Table 2. Table 2 Main properties of barite minerals Mineral name Chemical formula chemical components % dense degree g/cm 3 Moh's hardness Crystal system Shape Color Barite BaSO 4 BaO, 65.7 SO 3 , 34.3 4.5 2.5 ~ 3.5 Oblique square Plate Columnar gray In addition, barite is difficult to contain water and acid, non-toxic, non-magnetic, and can absorb X-ray and gamma rays. V. Process characteristics and main uses Barite is an important bismuth-containing mineral with a specific gravity (4.3-4.7), low hardness (3-3.5), chemical stability, insoluble in water and acid, and barite powder is mainly used in petroleum , chemical, paint, In the industrial sector such as fillers, 80%-90% of them are used as mud weighting agents in oil drilling. Table 3 lists its main uses. Table 3 Main uses of barite Application field the Lord want use way Prepare Note Oil drilling Circulating mud weighting agent in rotary drilling of oil and gas wells Cool the drill bit, take away the chipped debris, lubricate the drill pipe, close the hole wall, control the oil and gas pressure, and prevent the oil well from spraying Chemical industry Production of various antimony compounds such as barium carbonate, barium chloride, barium sulfate, zinc barium white, barium hydroxide, barium oxide These antimony compounds are widely used in reagents, catalysts, sugar refining, textile, fire protection, various fireworks, synthetic rubber coagulants, plastics, insecticides, steel surface quenching, phosphors, fluorescent lamps, fluxes, grease additives, etc. glass Oxygen scavenger, clarifying agent, flux Increase the optical stability, gloss and strength of the glass Rubber, plastic paint Filler, brightener, weighting agent building Concrete aggregate, paving material Heavy pressure buried pipelines in marshes, instead of lead plates used for shielding of nuclear facilities, atomic energy factories, X- ray laboratories, etc., extending the life of pavement Sixth, product quality standards Barite products have different specifications and quality requirements depending on their application. Barite powder for oil drilling The quality requirements for barite powder for drilling in China's oilfield are listed in Table 4. Table 4 Quality requirements for barite powder for oil drilling item Head Means Standard Prepare Note Density, g/cm 3 ≥4.2 Fineness, — 200 mesh % — 325 mesh % ≥97 ≥85 ~ 90 Water soluble, % ≤0.1 Clay effect, Pa · s ≤0.125 Viscosity before and after adding 1% gypsum Barium sulfate content, % ≥90 The national standard for barite powder has been formulated. The water-soluble salt (calculated as calcium) is not more than 250 ppm; the 200 mesh residue is not more than 3%, and the 325 mesh residue is not more than 5%. The barite for chemical barite chemical industry is divided into three grades. The required indexes are: BaSO4, SiO2, Fe2O3, Al2O3 and water-soluble salts. See Table 5 for details. Table 5 Classification of chemical barite Product level Means Standard, % BaSO 4 SiO 2 Fe 2 O 3 Al 2 O 3 Water soluble salt Level I 95 < 1.5 < 0.5 < 1 < 0.3 Level II 90 < 2.5 < 1.5 < 2 < 1.0 Level III 85 < 2.5 < 1.5 < 2 < 1.0 The quality requirements for barite powder produced by barite powder paint, rubber filler, ordinary glass, and zinc bismuth in other departments are listed in Table 6. Table 6 Quality requirements for barite powder for paints, etc. Uses want begging Means Standard Prepare Note BaSO 4 ,% CaCO 3 ,% Fe 2 O 3 ,% Through particle size, mesh paint 90 ~ 95 0.05 < 325 Requires high whiteness Rubber filler > 98 < 0.36 Trace <325 Do not allow impurities containing Mn , Cu , Pb Ordinary glass > 96 < 0.1 < 0.2 60 SiO 2 <1.5%, Al 2 O<0.15% Production of zinc white 95 ~ 98 < 1 SiO 2 <1%, the less Al 2 O 3 the better International Trade Product Grade In international trade, barite is generally divided into three grades according to different purposes. See Table 7 for details. Table 7 International trade product grade level want begging Means Standard Drilling level Density ≥ 4.2g/cm 3 , BaSO 4 ≥ 92%, 200 mesh sieve residue less than 3%, 325 mesh sieve residue less than 5% Chemical grade BaSO 4 > 95%, Fe 2 O 3 and SrSO 4 content not exceeding 1% , only a small amount of silicon oxide and calcium oxide are allowed Paint level High whiteness, fineness at least through 325 mesh 7. Barite beneficiation method Depending on the nature of the ore, the size of the mine, and the use, there are mainly re-election and flotation methods. Re-election mainly includes methods such as washing, de-sludge, sieving, jigging, shaker, spiral chute. The flotation is mainly positive flotation. Under the action of flotation agent, the barite is separated from the impurities such as galena, sphalerite, pyrite, silica and silicate. 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. Ore type Ore type Ore characteristics Major minerals and associated minerals Sedimentary type Block or stripe and bean grain structure Barite, quartz, clay minerals, such as pyrite Hydrothermal type Dense, gray to white Barite, pyrite, copper ore, galena, sphalerite, hematite, fluorite, etc. witherite Volcanic sedimentary type Barite, siderite, mirror iron ore, etc. Residual slope type Easy to choose, high grade Barite, fluorite, calcite , quartz, etc. Main ore processing method for barite Mineral processing method Principle of mineral processing Application range Hand selection The difference in color, density, etc. between barite and associated minerals Bulk barite Re-election Density difference between barite and associated minerals Processes including washing, deliming, sieving , jigging, shaker, etc. are mostly used for residual ore Flotation Differences in surface physicochemical properties between barite and associated minerals Commonly used in sedimentary barite ore and hydrothermal barite ore associated with sulfide ore, fluorite, etc. magnetic separation The magnetic iron oxide and barite difference minerals Mainly used to remove iron oxide mineral impurities Process flow Residual barite ore is generally selected by re-election method, that is, after washing, crushing, sieving, quartet concentrate is selected by jigging or other re-election method. The beneficiation process of sedimentary and hydrothermal barite ore, for sedimentary and hydrothermal barite ore, can not meet the requirements of users by re-election method, and needs to adopt flotation. Especially when barite is symbiotic with sulphide ore such as galena, sphalerite, pyrite, fluorite, calcite, etc., it can only be effectively separated by flotation. 8. General requirements for barite flotation process 1. Grinding fineness: Flotation of barite generally requires grinding fineness - 200 is 85~90%, usually with the first section of grinding-classifier overflow into the cyclone, through the cyclone After the classification, the second stage of grinding is carried out, and the optimum grinding fineness needs to be determined experimentally. 2. Stirring: It is better to use a strong secondary stirring tank. 3, flotation: the process is generally a rough sweep (some have no sweep) five to six selections, the mine can return or the first fine, the second fine returns, the third to the fifth fine re-select Immediately after the tail. The selection of flotation is a feature of barite flotation. 9. Barite flotation agent As the regulator of barite flotation, it is mainly water glass and sodium carbonate. Sometimes, when the ore is complicated, other inhibitors are added. The collectors are mainly oleic acid, oxidized paraffin soap, sodium petroleum sulfonate, etc. The advantage of the agent in actual production is that the medicament is conventional, the flotation cost is low, the operation is convenient, and the like, but there are mainly the following disadvantages: the selectivity is poor, and it is difficult to achieve a higher concentrate taste. The large amount of concentrate foam makes it difficult to transport and concentrate the concentrate, and it is easy to run.
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