Phosphoric acid plant is examined in this article. Phosphoric acid plants work well with a large number of phosphate rocks of different origins and qualities, including the lowest grade. Phosphoric acid (H3PO4) is produced by 2 commercial methods Unspoken Phosphoric Acid.
Wet process phosphoric acid is used in fertilizer production. In this process, the acid has a much higher purity and is used in the manufacture of high-grade chemicals. Medicines, detergents, food products, beverages and other non-fertilizer products are made from this citric acid. The thermal trend of demand for phosphoric acid has increased by approximately 2.3 to 2.5%. In the wet process, a significant amount of acid is produced. Cold water is produced with high concentrations of phosphorus and fluoride. This extra water in Cooling ponds (used to temporarily store excess precipitation for subsequent evaporation) are collected. Allows recycling of process water to the plant for reuse. Cooling water can be purified to an acceptable level of phosphorus. In the wet process, by the reaction of sulfuric acid (H2SO4) with naturally occurring phosphate rock, it is dried, crushed and then continuously fed into the reactor with sulfuric acid. It combines calcium from phosphate rock with sulfate and usually forms calcium sulfate (CaSO4), which is called gypsum. The gypsum is separated from the reaction solution by filtration. Hemihydrate process that produces calcium sulfate with half a molecule of water (CaSO4 ½ H2O). This one-step hemihydrate process has the advantage of producing a phosphoric acid wet process with a This process has a higher P2O5 concentration and less impurities than the hydrate process. Some companies have recently turned to the hemihydrate process. However, since most phosphoric acid is produced in the wet process, it will not be a hemihydrate process. A simple reaction for the hydrate process is as follows:
Ca (1) 3(PO4)2 3H2SO4 6H2O → 2H3PO4 3[CaSO4 2H2O]
In order to make the strongest phosphoric acid and reduce evaporation costs, 93% sulfuric acid is commonly used. Because the appropriate ratio of acid to rock is in the reactor. During the reaction, gypsum crystals precipitate and are separated from the acid by filtration. The separated crystals must be thoroughly washed to obtain at least 99% of the filter. After washing, the slurry gypsum is pumped into a gypsum pool and the water is siphoned and recycled through the phosphoric acid wave cooling pool. Approximately 0.3 hectares of pond area and water ventilation are required per mg. Significant heat is generated in the reactor. In older plants, this heat is cooled by blowing air onto the surface of the hot slurry, then recycling it back into the reactor. Wet process phosphoric acid typically contains 26 to 30% P2O5. In most cases, acid It needs to be more focused to meet the phosphate nutrient profile for fertilizer production. Depending on the fertilizer produced, phosphoric acid is usually concentrated up to 40. The major emissions from wet process acid production include gaseous fluorides, mainly silicon. Tetrafluoride (SiF4) and hydrogen fluoride (HF) Phosphate rock contain 3.5 to 4.0% fluoride. In general, part of the fluoride is precipitated from the rock with gypsum, another part is washed away with a phosphoric acid product, and the remaining part is reactor or steamed. Evaporator The relative amounts of fluoride in filter acid and gypsum depend on the type. The stone and operating conditions of the final disposal of the escaped flora depend on the design and operation of the plant. Scrubbers may be used to control fluorine release. Washing systems used in phosphorus acidic plants include venturi, wet and semi-flow washing machines. Leachate may precipitate fluoride in sedimented ponds. If the pool water is saturated with fluoride, fluorine gas may be released into the atmosphere. The reactor in which the phosphate rock reacts with sulfuric acid is its main source. Fluoride emissions accompany the air used to cool the reactor slurry. Because air emissions are minimized, cooling has largely replaced the air cooling method. Closed system Evaporation of acid concentration is another source of fluoride emissions. About 20 to 40% of the fluoride in the rock is evaporated in this operation. Thermal process acid production Raw materials are essential for the production of phosphoric acid by the thermal process. Yellow phosphorus, air and water are needed. This process consists of 3 main steps:
(1) Combustion
(2) Hydration
(3) Hydrated
In combustion, liquid phosphorus is burned (oxidized) in ambient air. The combustion chamber is heated to 1650 to 2760 ° C (3000 to 5000 ° F) to form phosphorus. Phosphorus pentoxide is then diluted with H3PO4 or hydrated with water. A strong phosphoric acid liquid is produced. It is done with high pressure drop demistors. The concentration of phosphoric acid (H3PO4) produced by the thermal process is usually from 75 to 85%. This high concentration is required for the production of high-grade chemicals and other items. For non-fertilizer production, efficient plants recover about 99.9% of the basic elements. Phosphorus is burned as phosphoric acid. The main source of emission from the thermal process is H3PO4 dust in the gas from the hydrator flow. The size of acid dust particles is from l.4 to 2.6 micrometers. There is about half of the total P2O5 as liquid phosphoric acid particles. Efficient plants with different control equipment have an economic incentive to control these potential losses. Control equipment commonly used in the phosphoric heat process. Acidic plants include venturi washers, cyclonic separators with mist removers, and fiber wires. Phosphoric acid plants are highly adjustable for processing several types of phosphate rocks and maximizing plant yields.