Method for preparing high-purity calcium aluminate

Abstract

The invention provides a method for preparing high-purity calcium aluminate, and relates to the field of preparation of raw materials of water purifying agents. The method comprises the specific stepsthat (1) 95-125 kg of aluminum hydroxide and 30-40 kg of pure limestone are mixed in proportion to obtain a mixed raw mineral material; (2) the raw material is placed into a rotary kiln, natural gasor coal gas is sprayed into the rotary kiln and burns in the kiln, the rotary kiln keeps rotating, and calcining is conducted at 1,100-1,450 DEG C for 30-60 min; (3) after calcining is completed, natural cooling is carried out, and a white block object is crushed to obtain the high-purity calcium aluminate. By means of the method, the natural gas or coal gas is directly used as fuel for calciningthe mixed minerals, impurities can be greatly reduced, the product purity is improved, and the production efficiency is also greatly improved.

Description

technical field [0001] The invention relates to the technical field of preparation of water purifying agent raw materials, in particular to a method for preparing high-purity calcium aluminate. Background technique [0002] Calcium aluminate powder is a white powder, the main ingredient is calcium dialuminate (CaO 2A1 2 o 3 ) and calcium aluminate (CaO·A1 2 o 3 ) mixture, slightly soluble in water, the aqueous solution is alkaline, with a pH value of about 11. Calcium aluminate powder is the raw material of water purifier. The production of water purifier by acid-soluble one-step method can save a lot of manpower and electricity, and can greatly reduce the cost. It also has the advantages of simple process equipment and easy mastering. It is an ideal raw material for the production of basic aluminum chloride and polyaluminum chloride products. [0003] Calcium aluminate powder has a high reactivity with inorganic strong acids and can be started at room temperature. And...

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Problems solved by technology

[0004] CN106006689A provides a preparation method of calcium aluminate for water treatment agent, the firing temperature is 800-900°C, and the dissolution rate of alumina is 97.8%, but due to the low firing temperature, the influence of impurities in the raw material cannot be eliminated

[0005] CN103950959A provides a method for preparing pure calcium aluminate powder for water treatment agent with a vertical kiln. The calcination temperature is 1350-1460°C. Petroleum coke powder and boron-containing compounds are added. Due to the addition of many other raw materials, the product The mass fraction of Al2O3 in medium cannot be further increased, currently it is about 57-68%, the mass fraction of Calcium Oxide is about 30-42%, and the mass fraction of soluble Al2O3 is about 53-64%.

However, the technology has no specific data details, nor does it report the treatment of impurities