41results about How to "Lower magnesium levels" patented technology

Belonging to the technical field of inorganic chemical industry, the invention provides a technology for preparation of low-magnesium phosphate concentrate and byproducts calcium carbonate and magnesium oxide from medium and low grade phosphate rock. The technology includes the steps of: calcining medium and low grade phosphate rock at 900-1100DEG C; and then carrying out slaking, leaching, precipitation and a series of treatment to obtain low-magnesium phosphate concentrate, calcium carbonate and magnesium oxide. The technology maximumly retains phosphorus element in the prepared low-magnesium phosphate concentrate, and produces calcium carbonate and magnesium oxide as the byproducts, so that the calcium, magnesium and phosphorus elements in the medium and low grade phosphate rock can be fully utilized. In the obtained low-magnesium phosphate concentrate, calcium carbonate and magnesium oxide products, the low-magnesium phosphate concentrate has a phosphorus pentoxide content of more than 37% and a magnesium oxide content of less than 0.5%, the calcium carbonate has a calcium oxide content of more than 50%, and the magnesium oxide has purity of over 94%. Therefore, the increase percentage point of phosphorus pentoxide in the low-magnesium phosphate concentrate is over 10.13.

A method for reducing content of magnesium in feed grade calcium hydrophosphate is characterized in that a purified liquid obtained after defluorination and purification of phosphoric acid by a wet process with sulfuric acid or phosphorus wastewater of the phosphorus chemical industry is subjected to neutralization reaction with lime cream, sulfuric acid is added after reaction to reduce the content of magnesium in a reaction slurry solid phase, the adding amount of sulfuric acid is 0.5-1.3 times of stoichiometric ratio of the magnesium content in a reaction endpoint slurry solid phase, slurry is filtered after the reaction, and a feed grade calcium hydrophosphate product is obtained after a filter cake is dried; and a separated liquid phase is added into the lime cream, neutralized to the pH value of 8-10 and then filtered, and filtrate is recycled. The method can effectively reduce the content of magnesium in feed grade calcium hydrophosphate, the calcium content can be improved, and the method has the characteristics of simple and effective process, easiness in reaction operation and good economic benefit.

The invention discloses a method for producing superfine slag powder by using copper smelting secondary slag. The method comprises the process steps: melting at a high temperature, water quenching, granulating, levigating, performing magnetic separation, extracting iron, airing and drying the copper smelting secondary slag, filling the slag into grinding equipment for grinding, adding a grinding aid triethanolamine and adding chemical activators such as gypsum, calcium hydroxide and sodium sulfate in the grinding process, levigating until the specific surface area is larger than 400m<2> / kg, thereby obtaining the superfine slag powder. The method has the following advantages that the conventional acid slag with low utilization rate of binding material is successfully prepared into the superfine slag powder which can be used for a cement admixture or a concrete additive; the magnetic separation tailings with a certain fineness are further ground, and one part of chemical activators achieve grinding aiding effects in the grinding process, so that the grinding energy consumption is reduced, and the cost is reduced; and moreover, the chemical additives can be replaced by industrial waste residues, for example, calcium hydroxide is replaced by carbide slag, industrial sodium sulfate is replaced by mirabilite, the cost can be greatly reduced, and the environment-friendly effects are further increased.