Abstract: A method for growing bulk boron arsenide (BA) crystals, the method comprising utilizing a seeded chemical vapor transport (CVT) growth mechanism to produce single BAs crystals which are used for further CVT growth, wherein a sparsity of nucleation centers is controlled during the further CVT growth. Also disclosed are bulk BAs crystals produced via the method.

Abstract: The present invention relates to a lithium metal powder, a preparing method thereof, and an electrode including the same, wherein the method for preparing the lithium metal powder includes: providing a lithium metal material and a ultrasonication solution; mixing the lithium metal material and the ultrasonication solution to form a mixed solution; and ultrasonically vibrating the mixed solution to form a lithium metal powder, wherein the lithium metal powder is covered by a protective layer, and the aforementioned protective layer includes a protective layer material, wherein the protective layer material includes a sulfide, fluoride, or nitride, or a combination thereof.

Abstract: Disclosed is a microwave chemical method for totally extracting fluorine and rare earth from bastnaesite concentrate, including: alkaline conversion defluorination of bastnaesite through microwave irradiation, microwave-assisted leaching of fluorine, solid-liquid separation of leaching solution and microwave-assisted leaching of rare earth. The rare earth hydrochloric acid solution for leaching contains no fluorine ion, so that the fluorine interference of subsequent processes such as impurity removal can be completely avoided; the fluorine and the rare earth are leached with microwaves, which does not need the stirring, so that the automatic control is easy to implement; the fluorine and rare earth leaching speed is high, the leaching time is short and the complete leaching of fluorine and little residual alkali in the slag can be realized by two-time leaching; and no fluorine-containing waste water is discharged, and the total extraction of the rare earth can be realized by one-time leaching.

Abstract: The present invention belongs to the field of recovery of secondary resources of noble metals, and discloses a method for leaching platinum group metals from spent catalyst by UV-vis, which uses ferric oxalate complex/hydrogen peroxide-chloride salt solution as a solvent for extracting platinum group metals under the condition of UV-vis, converts the platinum group metals from metallic state to platinum group metal complex, and obtains platinum group metal lixivium to realize the leaching of the platinum group metals. The platinum leaching rate of the method of the present invention can reach more than 97%. The present invention has mild reaction conditions, realizes the green recovery of platinum group metals from spent catalyst, avoids the use of strong acids and bases and toxic substances and avoids the production of toxic gases in the leaching process, so as to reduce the environmental hazards of the spent catalyst.

Abstract: The present invention provides a method for treating a copper-containing waste etching solution, which includes: preparing basic copper chloride nanometer seed crystals and synthesizing basic copper chloride mono-crystals; making an acidic waste etching solution subjected to agglomeration reaction with an ammonium-containing solution and slurry containing the basic copper chloride mono-crystals to obtain basic copper chloride crystal particles and copper-removed waste solution; making an alkaline waste etching solution react with sulfuric acid to obtain a copper sulfate mixed solution; and then evaporating, concentrating, cooling and crystallizing the copper sulfate mixed solution obtained by the reaction of the alkaline waste etching solution and the sulfuric acid in sequence to obtain copper sulfate pentahydrate solids.

Abstract: Salt production can include preparing hydrohalite particles by crystallization from saturated brine, adding the hydrohalite particles to a salt brine, thereby forming a hydrohalite-salt brine mixture, agitating the hydrohalite-salt brine mixture until the hydrohalite particles have decomposed into NaCl crystals, and filtering out the NaCl crystals from the salt brine. In some instances, an initial temperature of the salt brine prior to adding the hydrohalite particles is at least 0° C. In some instances, a ratio of salt brine to hydrohalite particles, by weight, is from 0.4 to 29.

Abstract: The invention relates to a method and an assembly for recovering magnesium ammonium phosphate from slurry supplied to a reaction container (10) in which an aerobic milieu that is alkaline as a result of CO2-stripping is present and in which the slurry is guided in a circuit with the aid of ventilation. Cationic magnesium, such as magnesium chloride, is added to the slurry, and magnesium ammonium phosphate crystals which are crystallized out of the slurry are removed via a removal device (30) provided in the base region of the reaction container. The slurry is supplied from the first reaction container (10) to a second reaction container (12) via a first line (14), wherein an anaerobic milieu is set in the second reaction container in order to redissolve the phosphate, and MAP crystals crystallized in the second reaction container are supplied to the first reaction container.

Abstract: The disclosure discloses a method for preparing calcium oxide using multistage suspension preheater kiln. The steps of the method are: (1) the limestone powder is fed to the multistage suspension preheater kiln for preheating to 800° C. to 900° C.; (2) A preheated material is fed to a decomposition furnace, and calcined at 900° C. to 1100° C. for 25 s to 35 s; (3) A calcined material is fed to a rotary kiln, and calcined at 1100° C. to 1300° C. for 25 to 35 minutes, and finally cooled to obtain calcium oxide.