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.

The invention discloses a method for preparing refined industrial salt low in calcium and magnesium by utilizing an underground denitration process. The method disclosed by the invention comprises the following steps: (1), injecting alkali production calcium liquid in a well and extracting brine; (2), underground removing sulfate radicals and magnesium; (3), surfacely removing calcium; (4), producing salt in vacuum; and (5), returning salt production mother liquid in the well and denitrating. The content of calcium and magnesium in industrial salt produced by the method disclosed by the invention is less than or equal to 0.05%, and therefore, the content of calcium and magnesium is far less than that in industrial salt produced by the traditional methods.

The invention discloses a method for removing magnesium from an ultralow-quality phosphate rock and producing magnesium hydroxide. The method comprises the steps as follows: mixing phosphate rock powder with a magnesium remover for magnesium removal reaction, carrying out solid-liquid separation, obtaining solid-phosphate concentrate, and adding a neutralization and sedimentation agent into liquid to obtain a magnesium byproduct. The method is characterized by taking the ultralow-quality phosphate rock as a raw material and mixed acid of sulphurous acid, sulfuric acid and fluorosilicic acid as the magnesium remover, carrying out solid-liquid separation, mixing washing water for washing a solid phase with a solution obtained after separation, and carrying out neutralization and sedimentation reaction. According to the method, mixed acid of sulphurous acid, sulfuric acid and fluorosilicic acid is adopted as the magnesium remover, so that the P2O5 loss is reduced; the process route is short, the operation is simple and the one-time investment cost is low; the magnesium removal rate can reach more than 80% and the content of magnesium in the obtained concentrate is lower than 1%; and the obtained phosphate concentrate is good in quality, the quality is improved by 5-10%, the P2O5 yield is high and can reach more than 99% under the optimal process conditions, and the P2O5 content is increased by 3-5% in general.

The invention provides cement produced by utilizing industrial solid wastes. The cement is prepared from the following raw materials: 77.00-82.50% of clinker, 0.30-7.90% of blaster furnace slag, 1.60-5.55% of desulfurization gypsum, 2.90-7.60% of waste rocks, 0-1.00% of high-silicon sandstone, 0.70-6.70% of fly ash, 0-12.00% of high magnesium waste rock, 0-2.40% of phosphogypsum and 0-0.80% of titanium gypsum, wherein the clinker is prepared from the following raw materials: common limestone, marble sawdust, marble leftover material, high magnesium waste rock, sandstone, red clay and wet-discharged fly-ash. According to the cement, the cement raw material is prepared by using the marble sawdust and leftover material, the waste residue utilization rate is high, and lots of natural resources and energy can be saved. Meanwhile, the high magnesium waste rock is used for preparing the raw material and serves as a mixed material of the cement to be simultaneously used, and the utilization rate of the high magnesium waste rock is greatly improved.

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 precipitated calcium carbonate production technology for reducing magnesium and increasing calcium. The technology comprises the steps as follows: 1) a desulfurizing tower is serially connected with a washing tower in kiln gas purification, and a desulfurizer is added to a liquid phase of the desulfurizing tower, so that the purification effect of a kiln gas is improved, and meanwhile, the dosage of circulating water is reduced; 2) a raw slurry pre-ageing process and a dynamic ageing process are adopted, the "back-mixing" phenomenon is avoided, and the ageing time of the raw slurry is ensured; 3) a carbonation reaction kettle adopts a stirring apparatus with three layers of paddles, so that the carbonation reaction time is shortened, and the utilization rate of the kiln gas is increased; 4) magnesium is separated out from mother liquor from which calcium carbonate is separated out by adopting a steam pyrolysis method, filtrate is returned to a digestive process, and cyclic utilization of water is achieved. The precipitated calcium carbonate product obtained by the technology is small in grain size (D50 is approximate to 4mu), high in whiteness (greater than or equal to 94), low in magnesium content (MgO is smaller than or equal to 0.5%), and low in alkalinity (pH is smaller than or equal to 9), and is more applicable to the industries of plastic steel and the like with special demands on the magnesium content, the whiteness, the alkalinity and the like besides of meeting the industries such as rubber, plastic, papermaking and coatings.

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.

The invention relates to the field of comprehensive utilization of salt lake resources. Specifically, the invention relates to a method for preparing magnesium-based intercalation functional materials and co-producing boric acid by using salt lake brine with a high magnesium-lithium ratio. The invention uses high-magnesium-lithium salt lake brine as raw material, adds certain soluble trivalent metal salts, fully utilizes magnesium resources in high-magnesium-lithium ratio salt lake brine by synthesizing magnesium-based layered functional materials, and then uses low-magnesium-lithium ratio hydrotalcite mother liquor to prepare boric acid. The preparation method of the magnesium-based functional material and boric acid provided by the present invention can not only effectively solve the problem of complex process, high cost, low utilization rate of salt lake resources, and "magnesium damage" formed in the production process of potash fertilizer in the previous methods, but also greatly reduce the cost of preparing boric acid Moreover, the abandoned magnesium resources can be fully utilized, the production cost of magnesium-based functional materials is reduced, and the high-value and comprehensive utilization of magnesium-boron resources in salt lakes is realized, which has good industrialization prospects.