Main features of magnesium sulfate fertilizer production technology

Magnesium sulfate fertilizer features:

1. Strengthen production and reduce investment. Taking sulphuric acid as an example, the sulfur dioxide concentration in the converter has increased from 10.5% in the 1970s to 12%. The gas flow rate of the converter catalyst layer was increased from 0.36 m/s to 0.45 m/s. Due to the increase in gas concentration and flow rate, the size of production equipment is reduced and construction investment is reduced.

2. Reduce system resistance and save power consumption. The traditional columnar catalyst is changed to a ring-shaped catalyst, which reduces the pressure drop of the converter with the largest resistance, and reduces the pressure of the packing layer with a large opening ratio for the drying and absorption towers, and reduces the height of the packing layer; Gas line length. All of these measures reduce the resistance of the production system, which saves power consumption.

3. Improve the utilization efficiency of waste heat. The new sulphuric acid plant uses the combustion heat of the sulphur-containing feedstock and the heat of conversion reaction to produce medium-pressure superheated steam for power generation. Recently, Monsanto Environmental Chemical Co., Ltd. of the United States has developed a technology that uses sulphur trioxide to absorb heat of reaction and produce low-pressure steam, which greatly improves the efficiency of waste heat utilization in the sulfuric acid industry. For sulphuric acid, the waste heat recovery efficiency has reached 90-95%.

4. Use corrosion-resistant materials to ensure reliable operation of the equipment. For critical parts that are susceptible to corrosion, stainless steel and alloys are widely used. For example, stainless steel shell-and-tube acid coolers, alloy plate heat exchangers or fluoroplastic acid coolers have been widely used to replace concentrated cast iron pipes to cool concentrated sulfuric acid; stainless steels have been used to make converters, heat exchangers and start-up preheaters.

5. Eliminate pollution. Two-rotation and two-suction processes are widely used to reduce exhaust gas pollution. A number of sulfuric acid tail gas treatment processes have also been developed to further reduce the amount of sulfur dioxide released into the atmosphere to less than 100 ppm or less. For the smelting of flue gas sulphuric acid and pyrite sulphuric acid, measures to separate harmful impurities and waste acid from the purification process are used to eliminate sewage pollution.

6. Large-scale and centralized production equipment. At present, the largest single series production capacity of smelting flue gas sulphuric acid equipment is 2.54 kt of sulfuric acid per day and 2.81 kt of sulphuric acid. Five sets of large-scale sulphuric acid production plants have been built in the New Wales factory in the United States, with a total production capacity of 11.5 kt per day. The large-scale production equipment reduces construction investment and production costs.

7, using electronic computers to control production. In the large-scale sulfuric acid plant built in the 1980s, many sulfuric acids were detected and controlled by electronic computers. Some old factories have also been remodeled and installed electronic computers. The use of an electronic computer to control production can optimize the operation, which is conducive to the stability of production and the reduction of cost.

As the world's population increases and food requirements increase, the production of fertilizers will further develop. As the main raw material for the production of phosphate fertilizer, magnesium sulfate fertilizer will also be rapidly developed. The development of the sulfuric acid industry in developing countries will be faster than that in developed countries.