Provided are magnesium oxide particles which are good in dispersibility in a resin or rubber, can function sufficiently as an acid acceptor or scorch retarder, and do not lower, even after combined with a resin or rubber, material properties thereof; a resin composition; a rubber composition; and a shaped body. The magnesium oxide particles satisfying the following (A) to (C): (A) an average particle size is 5 μm or less; (B) a BET specific surface area is 20 m.sup.2/g or more and 200 m.sup.2/g or less; and (C) a screen residue by a sieve opening of 45 μm is 0.1% by weight or less.

Provided are magnesium oxide particles which are good in dispersibility in a resin or rubber, can function sufficiently as an acid acceptor or scorch retarder, and do not lower, even after combined with a resin or rubber, material properties thereof; a resin composition; a rubber composition; and a shaped body. The magnesium oxide particles satisfying the following (A) to (C): (A) an average particle size is 5 μm or less; (B) a BET specific surface area is 20 m.sup.2/g or more and 200 m.sup.2/g or less; and (C) a screen residue by a sieve opening of 45 μm is 0.1% by weight or less.

The present invention disclosed use of lactam as a solvent in the preparation of nanomaterials by precipitation method, sol-gel method or high temperature pyrolysis. These methods are able to recycle lactam solvent, which meet requirements of environmental protection.

The present invention disclosed use of lactam as a solvent in the preparation of nanomaterials by precipitation method, sol-gel method or high temperature pyrolysis. These methods are able to recycle lactam solvent, which meet requirements of environmental protection.

A system and method of desalinating a brine stream are provided. The multistage desalination process with carbon dioxide capture recovers valuable products where the reject brine is passed through seven stages. In each stage, a specific metal ion is recovered. In stage 1, a ˜100% recovery of magnesium ions as magnesium hydroxide solid was obtained by chemical reaction with ammonia solution. In stage 2, Na.sup.+ reduction, as sodium bicarbonate, and CO.sub.2 uptake was achieved. In stage 3, electrocoagulation (EC) was used to recover sulfate ions as pure calcium sulfate solid and to regenerate NH.sub.3 as ammonium hydroxide. In stage 4, CaO was added to the treated brine. In stage 5, more recovery of NaHCO.sub.3 was attained by adding ammonium bicarbonate, while in stage 6, the treated brine mixture was passed through another modified Solvay process. In stage 7, EC was again used to recover CaCl.sub.2 solution and NH.sub.3 compounds.

A system and method of desalinating a brine stream are provided. The multistage desalination process with carbon dioxide capture recovers valuable products where the reject brine is passed through seven stages. In each stage, a specific metal ion is recovered. In stage 1, a ˜100% recovery of magnesium ions as magnesium hydroxide solid was obtained by chemical reaction with ammonia solution. In stage 2, Na.sup.+ reduction, as sodium bicarbonate, and CO.sub.2 uptake was achieved. In stage 3, electrocoagulation (EC) was used to recover sulfate ions as pure calcium sulfate solid and to regenerate NH.sub.3 as ammonium hydroxide. In stage 4, CaO was added to the treated brine. In stage 5, more recovery of NaHCO.sub.3 was attained by adding ammonium bicarbonate, while in stage 6, the treated brine mixture was passed through another modified Solvay process. In stage 7, EC was again used to recover CaCl.sub.2 solution and NH.sub.3 compounds.

Disclosed herein are system and methods to effectively leach coal ash with hydrochloric acid and separate an insoluble silica product and then selectively precipitate, from the leachate, a number to value-added, strategic, marketable products using a hydroxide reagent. The resulting precipitated products include iron, aluminum, magnesium, calcium, and a mixture of rare earth elements and transition metals. These can be separated as hydroxides or converted to oxides or carbonates. Using hydrochloric acid for leaching and converting the chloride to sodium chloride in the final step results in practically no waste for this process. The silica can be further purified using sodium hydroxide fusion or caustic leach methods and some minor streams from this process are recycled to minimize any waste stream. These systems and methods can be applied to a number of other industrial waste products such as red mud from the aluminum process, slag from steel furnaces, mine tailings, and other metal-bearing waste streams.

Disclosed herein are system and methods to effectively leach coal ash with hydrochloric acid and separate an insoluble silica product and then selectively precipitate, from the leachate, a number to value-added, strategic, marketable products using a hydroxide reagent. The resulting precipitated products include iron, aluminum, magnesium, calcium, and a mixture of rare earth elements and transition metals. These can be separated as hydroxides or converted to oxides or carbonates. Using hydrochloric acid for leaching and converting the chloride to sodium chloride in the final step results in practically no waste for this process. The silica can be further purified using sodium hydroxide fusion or caustic leach methods and some minor streams from this process are recycled to minimize any waste stream. These systems and methods can be applied to a number of other industrial waste products such as red mud from the aluminum process, slag from steel furnaces, mine tailings, and other metal-bearing waste streams.

Disclosed herein are system and methods to effectively leach coal ash with hydrochloric acid and separate an insoluble silica product and then selectively precipitate, from the leachate, a number to value-added, strategic, marketable products using a hydroxide reagent. The resulting precipitated products include iron, aluminum, magnesium, calcium, and a mixture of rare earth elements and transition metals. These can be separated as hydroxides or converted to oxides or carbonates. Using hydrochloric acid for leaching and converting the chloride to sodium chloride in the final step results in practically no waste for this process. The silica can be further purified using sodium hydroxide fusion or caustic leach methods and some minor streams from this process are recycled to minimize any waste stream. These systems and methods can be applied to a number of other industrial waste products such as red mud from the aluminum process, slag from steel furnaces, mine tailings, and other metal-bearing waste streams.

Disclosed herein are system and methods to effectively leach coal ash with hydrochloric acid and separate an insoluble silica product and then selectively precipitate, from the leachate, a number to value-added, strategic, marketable products using a hydroxide reagent. The resulting precipitated products include iron, aluminum, magnesium, calcium, and a mixture of rare earth elements and transition metals. These can be separated as hydroxides or converted to oxides or carbonates. Using hydrochloric acid for leaching and converting the chloride to sodium chloride in the final step results in practically no waste for this process. The silica can be further purified using sodium hydroxide fusion or caustic leach methods and some minor streams from this process are recycled to minimize any waste stream. These systems and methods can be applied to a number of other industrial waste products such as red mud from the aluminum process, slag from steel furnaces, mine tailings, and other metal-bearing waste streams.