Barite is a common mineral of barium. Its composition is barium sulfate. Its chemical composition is Bao 65.7%, so334.3%. It is an important industrial mineral raw material for the production of barium and barium compounds. Fodamon engineer will show you the beneficiation process and equipment of barite.
Taking barite deposits in China as an example, they are mainly divided into four types: sedimentary deposits, volcanic deposits, hydrothermal deposits, and residual deposits. According to the type of ore, the nature of the ore, the size of the mine and the purpose of use, currently commonly used barite beneficiation methods mainly include manual method, gravity method, flotation method, magnetic separation method and combined process.
Generally, the residual barite ore is easy to be separated, so the gravity separation method is preferred. In addition to gravity separation, flotation is also required for the separation of sedimentary barite ore and hydrothermal barite ore associated with sulfide ore and fluorite. Next, we will explain each barite beneficiation process and the barite beneficiation equipment used in each process one by one.
1. Manual beneficiation
After the raw ore is mined, it is a common beneficiation method for many small mines to use simple manual beneficiation. Due to the high geological grade and stable quality of some mines, qualified barite products can be selected by hand according to the color and density of barite and associated minerals. The barite with rich ore block is selected by hand separation method, the particle size is required to be 30-150 mm, BaSO4 is more than 95%, generally more than 92%. Generally speaking, the manual separation method is simple and easy to operate, and can be carried out without barite beneficiation equipment. It is suitable for small-scale beneficiation, but it has low productivity, high requirements for ore grade and serious waste of resources.
2. Gravity separation
Barite gravity separation is mainly based on the density difference between barite and associated minerals, including ore washing, screening, desliming, jigging, shaking and other technological processes, which are mostly used to deal with residual barite ore.
After ore washing, screening, crushing, grading and desliming, the high quality barite concentrate can be obtained by jig, shaker and other barite beneficiation equipment, and the product grade can reach more than 88%. Jaw crusher or impact crusher is generally used in crushing stage, and roll crusher is generally used in fine crushing operation. In the separation stage, heavy medium rotary separator, cone classifier, jig separator or shaker are used. When the distribution size of barite is larger than 2 mm, heavy medium separation and jigging separation can be used, but the upper limit of the particle size of heavy medium separation is 50 mm, and the upper limit of the particle size of wet and dry jigging separation is about 20 mm. When the distribution size of barite is less than 2 mm, the shaker can be used for separation, but the hydrocyclone must be used to remove the mud before the separation operation to improve the separation effect.
3. Flotation separation
The proportion of barite is relatively large, 4-4.6, which has good floatability. Barite flotation is mainly based on the difference of surface physical and chemical properties between barite and associated minerals. It is commonly used in sedimentary barite ore and hydrothermal barite ore associated with sulfide ore and fluorite.
In China, for example, barite deposits are rich and poor, and more than 80% of the deposits with proven reserves are associated with other minerals. Flotation method must be used for the separation of ores with fine inlaid particle size and tailings of gravity separation. There are two kinds of flotation processes for barite: positive flotation and reverse flotation. The purpose of reverse flotation is to remove alkali metal sulfide.
As a common salt mineral, the flotation process of barite can be divided into two types according to the adsorption form: one is to use anionic collectors such as fatty acid alkyl sulfate and alkyl sulfonate to adsorb on the surface of barite mineral in the form of chemical adsorption, so as to separate from other associated minerals. The other is to use the cationic amine collector to flotation barite in the form of physical adsorption. The efficiency of amine collector is low, and it is very sensitive to the influence of slime, because the anion collector is ideal. In general, NaOH can be added to the ball mill to adjust the pH value to 8-10, and water glass can be added to the pulp as an adjusting agent. Under the condition of solid concentration of 40% - 50%, oleic acid collector can be used for barite flotation.
4. Magnetic separation
The magnetic separation of barite is mainly based on the surface magnetic difference between barite and iron oxide minerals. Some barite minerals such as siderite are usually selected. Magnetic separation is usually used in combination with gravity separation to produce barite as raw material of barium based drugs with low iron content.
5. Combined process flow
Barite associated with sulphide ore is usually processed by gravity separation flotation combined process. Taking the barite quartz calcite type ore separation as an example, in the flotation gravity separation combined process, by adding sodium silicate and collector to the flotation cell to remove quartz impurities, the barite and calcite mixed ore is obtained, and then according to the density difference between calcite and other gangue minerals and barite, the gravity separation operation is carried out with jig, shaker and other gravity separation equipment, and finally the gravity is obtained Crystal concentrate.
The barite mines mined in the early stage are mostly high-grade ores, and the low-cost, low-tech manual selection method or gravity separation is usually adopted. However, with the low-grade barite ore and the complicated nature of the ore, the magnetic separation method, flotation method and combined beneficiation method are gradually widely used in the separation of barite ore. It is recommended that all mine owners formulate scientific and reasonable flotation process based on the mineral processing test report to avoid unnecessary economic losses.