Novel technique for producing sulfur from industrial waste gypsum

[0023] Example 1:

[0024] Using desulfurized gypsum and high-sulfur coal as raw materials and fuels, desulfurized gypsum is light yellow powder, moisture 12.1%, dry basis SO 3 The content is 44.3%, the low calorific value of high-sulfur coal is 4875×4.18KJ/kg, the total sulfur content is 6.3%, and the high-sulfur coal is crushed. The total material consumption ratio of desulfurized gypsum to coal is 30:70. The desulfurized gypsum is dried and dehydrated and fed into the roasting reduction furnace together with crushed coal. The temperature in the furnace is 900℃, rich in steam S and SO. 2 , CO, CO 2 , N 2 The high-temperature gas is sent to the secondary reduction furnace, and high-sulfur coal is still used as the reducing agent. The reduction temperature is 1000℃. The gas rich in S steam from the secondary reduction furnace is sent to the condensation collection tower, and the tail gas enters the low-temperature catalytic reduction furnace. Purify emissions.

[0025] Example 2:

[0026] The waste gypsum and anthracite discharged from the production of titanium dioxide from a certain place, the water content of the waste gypsum is 37%, and the dry basis SO 3 The content is 38.6%, the calorific value of anthracite is 5543×4.18KJ/kg, and the total sulfur content is 1.2%. It adopts combined vertical furnace reduction treatment to produce sulfur by-product cement clinker. Firstly, grind the supplementary silicon-aluminum raw materials and anthracite powder to a dry powder with a fineness of 80um and a sieve residue <14%, mix the dry powder and wet waste gypsum evenly, and shape it into a Φ12mm material rod. The ash content of the material rod is controlled to KH1 .0, N2.2, P1.5; The ratio of waste gypsum to coal is 80:20. The material rods are continuously added to the vertical furnace from the upper part of the combined vertical furnace. The drying and dehydration of the material rods is solved by a special heating system. The drying and dehydration exhaust gas is purified and discharged, and the dried and dehydrated material rods enter the high-temperature reduction reaction zone in the middle and lower parts. The heat source is provided by the coal contained in the rods, and the high temperature layer is 1450°C. The waste slag, the cement clinker, is continuously moved downward under the action of gravity to be cooled and discharged. The gas rich in S steam is discharged from the upper part of the vertical furnace and then enters the condensation tower. The exhaust gas is sent to the catalytic reduction furnace, and then discharged after purification.

[0027] Example 3:

[0028] Using a certain citric acid residue-lemon gypsum, wet material with gray odor, water content 32.7%, dry basis SO 3 The content is 42.6%, anthracite is used as the thermal reducing agent, the calorific value of the coal is 4987×4.18KJ/kg, and the combined vertical reduction reactor is used to produce sulfur and simultaneously produce cement clinker. First grind the coal crushed and supplemented shale and cinder ingredients into dry powder with 80um sieve remaining ≤ 12%, and then mix the dry powder and wet lemon gypsum ingredients into a Φ12mm rod. The ratio of waste gypsum to coal consumption It is 55:45, the clinker rate value is designed as KH 0.95, h 1.80, P 2.4; the material rod is added from the upper part of the combined furnace, and the special heat source is used for drying and dehydration. The dry and dehydrated material rod enters the high temperature reduction reaction in the middle and lower parts. Belt, the heat source is provided by the coal contained in the rods. The high temperature zone is about 1200°C. The waste residue formed at about 1200°C is gradually moved down and cooled and discharged. The 3-day compressive strength of the waste residue is 27.3MPa, the 28-day compressive strength is 48.9MPa, and the initial setting is 1 :13. The final setting is 1:52, and the safety is qualified. It can be used as cement clinker; the gas rich in S steam is discharged from the upper part of the vertical furnace into the condenser, and the tail gas is sent to the catalytic reduction furnace, and then discharged after purification.