A powder pulverization device is provided. The device includes a hermetically sealed pulverization container, a powder introduction mechanism having an introduction inlet opened inwardly to the pulverization container, and introducing powder to be pulverized to the introduction inlet, a powder pulverization mechanism disposed at a portion below the introduction inlet in the pulverization container, and a classification device disposed at a portion above the introduction inlet in the pulverization container for screening pulverized powder and leading the screened powder out from the pulverization container. An inner wall of the pulverization container is covered with a porous lining material and each hole of the lining material communicates with an air supply via a gap between the inner wall and the lining material.

The present invention relates to fine barium sulfate powder that can be readily and simply dispersed in resins or solvents; a resin composition, a coating composition, an ink composition, and a resin molded article each containing the barium sulfate powder; and a method for producing the barium sulfate powder. Provided is barium sulfate powder having a number average primary particle size of 1 to 100 nm, the powder including an organic compound on its surface, the powder in the form of compressed compact having a contact angle with distilled water of 10 to 170 degrees.

Systems and processes for producing potassium sulfate that include providing an industrial waste material that includes at least sodium sulfate, reacting the sodium sulfate with potassium chloride to produce a byproduct comprising potassium sulfate and a chloride-containing brine, and reacting the chloride-containing brine with barium chloride to produce barium sulfate and sodium chloride.

The present invention relates to processes employing water produced from wells that, after suitable purification steps, is processed to recover resources that can be used to treat other waste streams, such as flue gases and ashes from combustion of fossil fuels.

Provided is a friction material composition that can increase the coefficient of friction and the wear resistance, reduce the compressive deformation rate, and improve the yield upon hot forming, even when being free of copper component or having a small content of copper component. The friction material composition contains: titanate compound powder made of non-fibrous titanate compound particles; barium sulfate powder; and a thermosetting resin, wherein the titanate compound powder has an alkali metal ion dissolution rate of 15.0% by mass or less, the barium sulfate powder has a volume-based 50% cumulative particle diameter (D.sub.50) of 0.1 m to 20.0 m, and a content of copper component is 0.5% by mass or less in terms of copper element in a total amount of 100% by mass of the friction material composition.

The invention provides a low alpha dose barium sulfate particle having a silica content of 0.6% by weight or less and an alpha dose of 0.07 cph/cm.sup.2 or less.

The invention provides a low alpha dose barium sulfate particle having a silica content of 0.6% by weight or less, an average particle diameter of 1 m or less, a sulfur content of 10 ppm or less, and an alpha dose of 0.07 cph/cm.sup.2 or less.

The invention provides a low alpha dose barium sulfate particle having a silica content of 0.6% by weight or less and an alpha dose of 0.07 cph/cm.sup.2 or less.

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.

This invention prevents adhesion of powder to the inner wall of a pulverization container of a powder pulverization device. A powder pulverization device 10 comprises a hermetically sealed pulverization container 20; a powder introduction mechanism 30 having an introduction inlet 31a opened inwardly to the pulverization container 20, and introducing powder to be pulverized to the introduction inlet 31a; a powder pulverization mechanism 40 disposed at a portion below the introduction inlet 31a in the pulverization container 20 for causing high-pressure air to collide with powder, thereby pulverizing the powder; and a classification device 50 disposed at a portion above the introduction inlet 31a in the pulverization container 20 for screening pulverized powder and leading the screened powder out from the pulverization container 20, wherein an inner wall 20a of the pulverization container 20 is covered with a porous lining material 60A/60B and each hole 65 of the lining material 60A/60B communicates with an air supply device 62 via a gap 61A/61B between the inner wall 20a and the lining material 60A/60B.