Disclosed is a method of producing high-purity lithium carbonate and barium sulfate from discarded lithium secondary batteries, including: a first process for producing high-purity lithium phosphate from a discarded battery; and a second process for producing lithium sulfate from the lithium phosphate and producing lithium carbonate and barium sulfate from the lithium sulfate. The second process has steps of (a) producing a liquid mixture of lithium phosphate and sulfuric acid, (b) obtaining lithium sulfate by condensing the liquid mixture, (c) dissolving the lithium sulfate in water or a sodium hydroxide aqueous solution, depositing phosphoric acid as lithium phosphate, and performing solid-liquid separation (d) depositing lithium carbonate and performing solid-liquid separation to obtain lithium carbonate, (e) finely grinding the lithium carbonate and classifying the particles, (f) controlling a particle size and shape by dissloving edges of particles or minute particles, (g) performing solid-liquid separation, and (h) depositing barium sulfate.

Disclosed is a method of producing high-purity lithium carbonate from low-purity crude lithium carbonate. The method includes: (a) producing crude lithium carbonate slurry by mixing crude lithium carbonate having a polycrystalline state and a size of 20 to 200 m with water; (b) carbonating and dissolving the crude lithium carbonate slurry; (c) performing primary solid-liquid separation to obtain a filtrate; (d) adding soluble barium salts to the filtrate to deposit barium sulfate; (e) performing secondary solid-liquid separation for the filtrate containing the deposited barium sulfate to obtain a filtrate; (f) mixing lithium carbonate seed crystals with the filtrate obtained from the secondary solid-liquid separation and precipitating lithium carbonate dissolved in the filtrate on surfaces of the lithium carbonate seed crystals to produce high-purity lithium carbonate slurry containing high-purity lithium carbonate by controlling a particle size; and (g) carbonating the high-purity lithium carbonate slurry to produce high-purity lithium carbonate.

A drilling fluid composition that contains micronized barite particles with a particle size in the range of 1 to 5 m, and also a method of fracturing a subterranean formation using the drilling fluid composition. Various embodiments of the micronized barite particles and the method of making thereof, the drilling fluid composition, and the method of fracturing a subterranean formation are also provided.

A drilling fluid composition that contains micronized barite particles with a particle size in the range of 1 to 5 m, and also a method of fracturing a subterranean formation using the drilling fluid composition. Various embodiments of the micronized barite particles and the method of making thereof, the drilling fluid composition, and the method of fracturing a subterranean formation are also provided.

It is an object of the present disclosure to provide a method for inexpensively producing a high-performance barium sulfate powder which is obtained by using inexpensive barium sulfide as a raw material, has a high whiteness degree, and can suppress the generation of volatile components. A method for producing a barium sulfate powder comprises a step of heat treating a raw barium sulfate powders obtained by using barium sulfide as a raw material at 600 to 1300 C., wherein a retention time X (minutes) at a heat treatment temperature of t C. is more than time expressed by the following general formula: X (minutes)=A10.sup.6e.sup.(0.015t), where A is 8 or more, and an upper limit of X is 3000 minutes in the formula.

Hydrometallurgical processes are provided for the recovery of metal values, including cesium, from epithermal mineral deposits, including pharmacosiderite-containing ores. Aspects of the process involve the preferential formation of a cesium alum, and preparation of cesium hydroxide from the cesium alum.

A drilling fluid composition that contains micronized barite particles with a particle size in the range of 1 to 5 m, and also a method of fracturing a subterranean formation using the drilling fluid composition. Various embodiments of the micronized barite particles and the method of making thereof, the drilling fluid composition, and the method of fracturing a subterranean formation are also provided.

A drilling fluid composition that contains micronized barite particles with a particle size in the range of 1 to 5 m, and also a method of fracturing a subterranean formation using the drilling fluid composition. Various embodiments of the micronized barite particles and the method of making thereof, the drilling fluid composition, and the method of fracturing a subterranean formation are also provided.

A process for recovering lithium chloride from a lithium sulfate (Li.sub.2SO.sub.4)-containing mixture is described, comprising a step of sulfate removal using barium chloride (BaCl.sub.2). In embodiments, the process may further comprise one or more steps to reduce the level of one or more metals other than lithium and to reduce the level of sulfate by increasing the pH of the (Li.sub.2SO.sub.4)-containing mixture, e.g., using a calcium salt. In embodiments, treatments to reduce the level of one or more metals other than lithium, sulfate, and other components (e.g., calcium if used) may be used, producing a solution substantially comprising Li.sub.2SO.sub.4 for barium chloride (BaCl.sub.2) treatment, to form a precipitate comprising barium sulfate (BaSO.sub.4) and a solution substantially comprising lithium chloride.

A jet impingement reactor having a small, spheroidal reaction chamber is provided. The reaction chamber exhibits a first and a second fluid inlet arranged at opposite positions of the reaction chamber such as to point at one another, and wherein each of the first and the second fluid inlet comprises a nozzle. The distance between the nozzles is the same or smaller than the diameter of the reaction chamber along the first central axis. Preferably, the nozzles are comprised in fluid inlet connectors that are reversibly insertable into the wall of the reaction chamber such as to provide the first and the second fluid inlet. The invention further provides a method of mixing two fluids based on jet impingement using the reactor according to the invention.