Description

Phosphogypsum is the phosphate fertilizer industry solid waste, and phosphoric acid is the foundation of phosphate fertilizer industry. WPA production of sulfuric acid decomposition through phosphate rock formation extraction slurry, and then filter cleaning system in the phosphorylation. In the process of washing filters at the same time have a phosphogypsum waste. General production of one ton of phosphate per produces about six tons of phosphogypsum, the production of one ton per DAP emissions 2.5 **- 5 tons of phosphogypsum, our WPA yield about **0 million tons, With our high concentration of compound fertilizer industry in recent years the rapid development of phosphate fertilizer per year from the chemical industry from phosphogypsum about nearly *0 million tons. Phosphogypsum generally is powder , because contain 8 **- *5% , so it is paste-like , the particle diameter is generally 5 **- **0 Î&frac*4; m, the main ingredients is CaSO4 â�¢ 2 H2O, it usually is *0 **- *0 %, which contained elements of the secondary sources of ore vary, more complex ingredients are generally contain elements of rock, Ca, Mg phosphate, carbonate and silicate, In addition, a small amount of organic phosphorus, sulfur, fluorine compounds. Phosphogypsum general appearance of a gray, gray, Hui Huang, light yellow, light green, and other colors, the relative density is 2.*2 - 2.*7, the capacity is 0.**3 - 0.**0 g/cm3.ï&frac*4;�Because of their different manufacturers, their composition, color, physical properties and impurity content, types of impurities, and so the process and its principles vary, but they all have the following common characteristics: 1. Most of Phosphogypsum have a high level of attachment water, or a wet paste-like residue from the general, the attachment of the water content in the *0 **- *0%, or even higher individual 2. Phosphogypsum particle with smaller size, particle size are generally in the 5 **- **0 microns , during the production of gypsum powder, it can save grinding costs, but it will also generate large amounts of dust and increase the cost of removing dust 3. The ingredients of Phosphogypsum general contained are complicated, but contain less hardening of the plaster hydration properties greater impact on the chemical composition, PH value of the acidic rather than neutral. To the effective use of chemical gypsum brought more difficult. In phosphogypsum, effective component of the gypsum content are generally higher, up to *5 **- *5%, equivalent to more than two active ingredients in plaster. If the single-effective component of its content rather than its harmful impurities of the impact of industrial byproduct gypsum plaster can be as high-quality raw materials production. Therefore, if the use of appropriate technology and equipment, and to eliminate harmful ingredients in phosphogypsum the impact of phosphogypsum will become an inexpensive, high-grade, environmentally friendly production of quality raw materials. Brief introduction of production Because of the phosphoric acid generated by the vacuum belt phosphogypsum dehydration after dewatering machine containing more than *0% of the free water, with the domestic construction of phosphogypsum gypsum powder successful experience, gypsum pre-drying, boiling furnace calcined two-step process Calcined building gypsum powder. Specific for: loader will be sent to the raw materials from raw materials into the yard hopper, the metering conveyor belt into the rotary dryer drying to remove free water (that flow of heat for the coal-fired fluidized bed boiler, At the same time the increase in a conveyor belt in the acid-base and installations, and by measuring both the lime), the expected aggregate after Recoiler precipitator, an enhanced transportation equipment into boiling furnace calcined calcined (using coal-fired heat-conducting oil Furnace as a heat source), after calcination into the ball mill grinding modification, and upgrade transmission equipment after the upgrade cooked powder to reserve positions.