44 results about "Witherite" patented technology

This invention provides a molten steel composite refining additive. The said additive by wt.% includes aluminium ash 10-50% (aluminium content at least being 15% of ash wt.), metallurgical furnace slag 10-60%, carbide 5-65%, limestone 1-10% and witherite 1-10%. This additive is used for the oxidable slag tapping process of steel smelting furnace such as electric furnace, converter, etc. and for refining furnace to make the oxidable molten steel proceed polybasic composite oxygen removal, sulphur removal and quick deoxidated impurity inclusion removal, and at the same time, it enhances quick dissolution of added slagging material and quick slag forming.

The invention belongs to the technical field of chemistry, and concretely discloses a technology for producing barium chloride by taking witherite as a raw material. The technology comprises the following steps: mixing witherite and water, grinding and adding acid for acidolysis, adding salt and lime milk for removing impurity, falling film and pre-concentrating, evaporating and crystallizing to obtain barium chloride dehydrate crystals; cooling the crystal slurry and recrystallizing, recovering the barium chloride dehydrate crystals in a hot solution; merging the barium chloride dehydrate crystals and washing by saturated salt solution, recrystallizing and purifying, and drying to obtain the product barium chloride. The method has no restriction on witherite types, and raw material requirement is reduced, impurities removal step during the production process in a traditional mode is not required, flow is simple, operation is easy, no exhaust gas, waste residue and waste liquid is discharged during a whole process, and the technology accords with green chemical requirement, and the prepared barium chloride crystal has the advantages of high yield, high purity and low cost, and is suitable for large scale industrial production requirement.

The invention discloses a method for joint production of strontium nitrate and barium nitrate from high-calcium strontianite and witherite. The method comprises the following steps: respectively crushing high-calcium strontianite and witherite, mixing with water to obtain strontianite pulp and witherite pulp, subsequently adding nitric acid into the strontianite pulp, reacting, filtering to obtain a nitrate solution and strontium sulfate filter residue, adding hydrogen peroxide and activated carbon into the nitrate solution to react and decontaminate, subsequently evaporating to crystallize the decontaminated nitrate solution, centrifuging to obtain strontium nitrate and a mother liquid containing calcium nitrate, adding the witherite pulp into the mother liquid, reacting and filtering to obtain a solution with barium nitrate and calcium carbonate filter residue, removing the nitrate solution from the solution with barium nitrate, adding hydrogen peroxide and activated carbon for reaction and decontamination, and subsequently evaporating to crystallize the decontaminated barium nitrate solution to obtain barium nitrate and a mother liquid which mainly contains strontium nitrate. The method adopts high-calcium strontianite and witherite for joint production of strontium nitrate and barium nitrate, the raw materials are low in cost, the materials can be recycled, and thus environment pollution is avoided.

The invention discloses a technology for producing barium chloride by the witherite containing barium carbonate, which mainly comprises steps as follows: sulfur iron impurities are decomposed and oxidated to remove and the hydrated barium salt raw material liquid is prepared; the raw material liquid is electrically heated and concentrated in vacuum, which is driven by an axial flow pump, the solute is thermally crystallized to form the hydrated barium chloride dihydrate saturated crystalline; the crystallized hydrate is cooled to produce the serial barium salt products, wherein the vacuum heating condensation crystallization is a continuous production process; the whole technological process is implemented in the closed state; the by-products could be recycled; the crystallisation processis completed at one time and the production process is continuous. The products manufactured in the technological process has low impurity content, saves energy, is adaptive to the large-scale industrialization production and reduces the pollution and resource waste to a large extent.