Calcium hydroxide is obtained from the chemical reaction of calcium oxide and water, and is a traditional product of inorganic chemical industry. The processing method of high-purity calcium hydroxide is more complicated than that of ordinary calcium hydroxide, and it needs to use raw materials with high activity and low impurity content for processing. With the increase in market demand, the quality of calcium hydroxide on the market is also mixed, which needs to be carefully identified.
The process of high-purity calcium hydroxide processing
1. Primary screening
Take limestone and coke for calcination, and calcined calcium oxide with a vibrating screen of 5~15mm to remove the “plain ash” with more impurities, and then crush it to about 5~25mm to obtain more than 90% effective components. High-activity calcium oxide is supplied to the pre-digester through a constant-weight feeder through an air-tight regulator. To remove iron, sulfate and other impurities in slaked lime, first of all, the quality of raw and fuel materials must be strictly controlled, and raw and fuel materials with high iron content (including other oxides) are strictly prohibited from entering the site.
2. Preliminary digestion
According to the quality of calcium oxide and the ratio of supply, according to the range of water-to-calcium ratio of 0.55~0.80, use the control valve to automatically adjust the amount of water added, so that it is mixed and stirred in the pre-slider for 5~15 minutes for preliminary digestion, and the digestion temperature is controlled to 90 ~190°C, and then sent to the ripener for further digestion for 10~40 minutes to ensure complete digestion reaction.
3. Complete digestion
The completely digested calcium hydroxide enters the air separation separator for separation. According to the principle of centrifugal force and centripetal force, the large and small particles are separated by adjusting the separation value. point.
4. Screen again
The high or low calcium hydroxide content depends on the ore. First, the CaO content of limestone is required to be greater than or equal to 54%, and the content of other oxides cannot exceed the standard. Then, calcined and digested properly, calcium hydroxide with high calcium content can be obtained. For industrial calcium hydroxide, the effective calcium hydroxide content should be detected according to the product standard analysis method. The vibrating screen of 3mm~0.5mm or smaller can be exchanged according to the product’s requirements for purity, and the material under the sieve enters the vibrating mill and then undergoes air separation to improve the digestion yield of calcium oxide, and the material on the screen is used as coarse powder. The scum is drained.
Advantages of high purity calcium hydroxide
1. High activity, up to 300ml or more.
2. High purity, calcium oxide content is more than 72%.
3. Low impurity content, less than 1.70% of silica, alumina, iron oxide and magnesium oxide, and less than 1.10% of carbon dioxide.
3. The yield is high, can reach more than 95.1%, and can be mass-produced.
4. High fineness, low moisture content, use 590μm sieve with a sieve allowance of 0.00, 149μm sieve allowance <5%, and 44μm sieve allowance <10%.
5. It can meet the requirements of chemical production such as epichlorohydrin and high-efficiency bleaching powder, and can replace caustic soda, saving a lot of caustic soda and energy.
The above is the introduction of high-purity calcium hydroxide processing technology. In the process of calcium oxide digestion, it is also necessary to strengthen water quality management and calcium hydroxide line equipment management, improve calcium hydroxide production line, and produce high-purity calcium hydroxide.
The refinement of industrial production requires the production of higher-purity products. Only products that meet the development needs of the times can win the market competition and win market recognition. If you want to know about calcium hydroxide production line equipment, please call or leave a message on the website for details!