Production technology for preparing calcium oxide and sulfur dioxide through utilizing desulfurized gypsum

Abstract

The invention discloses a production technology for preparing calcium oxide and sulfur dioxide through utilizing desulfurized gypsum. The technology comprises the following steps: drying desulfurized gypsum at 230-300DEG C for 0.5-1.5h, wherein drying pretreatment is carried out at 40-50DEG C for 0.5-1h if the water content of carbon is above 5%; screening the desulfurized gypsum and the carbon for controlling the gypsum particle size below 40mum and the carbon particle size below 187.5mum; and mixing the screened carbon and the screened desulfurized gypsum according to a carbon-to-calcium sulfate mole ratio of 1:1-1.2:1 to obtain a mixed sample, putting the mixed sample in a high temperature reaction device, and reacting at 1000-1100DEG C under the protection of nitrogen or an inert gas under a gas flow velocity of 4-10m/s for 10-15min. The technology has the advantages of high reaction efficiency, fast reaction speed, less carbon consumption, high finally-obtained product quality, and no atmospheric pollution.

Description

technical field [0001] The invention belongs to the production field of calcium oxide and sulfur dioxide, in particular to a production process for preparing calcium oxide and sulfur dioxide by using desulfurized gypsum. Background technique [0002] China is the world's largest sulfur dioxide emitter. The conditions of coal-based energy resources determine that China's coal-based energy consumption structure will not change for quite a long time. With the continuous optimization and adjustment of the energy consumption structure, the new coal consumption in the future will be mainly used for power generation. Currently, coal-fired power plants provide about 80% of China's total electricity generation. It is expected that by 2020, about 60% of electricity generation will still come from coal-fired power plants. By the end of the "Eleventh Five-Year Plan", the sulfur dioxide emissions of thermal power plants are still on the rise. However, there are 300 million kW coal-fir...

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Problems solved by technology

Phosphogypsum CaSO 4 The content is low and also contains P 2 o 5 , F - and other harmful ingredients, which will affect product quality and cause corrosion to equipment

[0006] 2. Using coal gas or natural gas to burn and heat, the concentration of carbon dioxide produced is relatively high. According to the principle of chemical balance, carbon dioxide will inhibit the formation of the main product calcium oxide, and the output is low

In addition, due to the inclusion of air, it will not only increase the consumption of carbon, but also inevitably produce NO when the temperature is above 1000 °C x Harmful gases such as sulfur dioxide will affect the utilization rate of sulfur dioxide. If not handled properly, it will also cause air pollution

[0007] 3. The particle size of the phosphogypsum and carbon used is too large, and the reactants cannot be fully contacted, resulting in a long reaction time and incomplete reaction

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