A rapid, centrifugal method to prepare polysilazanes and separate them from their ammonium halide-anhydrous, liquid ammonia by-product is coupled with several, alternative methods to recover ammonium halide and anhydrous, liquid ammonia from the by-product. Some reactive modes of by-product recovery lead to sodium chloride as the sole waste product of, optionally, to ammonia borane as a secondary product of the process.

A method of purifying a crude lithium bis(fluorosulfonyl)imide, includes adding a water removal agent to a pretreatment liquid containing the crude lithium bis(fluorosulfonyl)imide to perform a dehydration reaction at a temperature ranging from 20? C. to 40? C., reacting the same for an additional 1 h to 6 h after an acid gas stops escaping from the reaction system, and filtering the reaction system to obtain a filtrate; the water removal agent is bismuth trichloride or antimony trichloride. Evaporating and concentrating the filtrate, and recrystallizing the concentrated filtrate are performed to obtain a purified lithium bis(fluorosulfonyl)imide.

A lithium bis(fluorosulfonyl)imide, a preparation method therefor and an application thereof, wherein iminodisulfonic acid is synthesized by using sulfur trioxide and ammonia as raw materials, the iminodisulfonic acid is chlorinated by means of thionyl chloride to obtain bis(chlorosulfonyl)imide, and then fluorination and lithiation are performed in sequence to obtain the lithium bis(fluorosulfonyl)imide. The method has excellent yield and purity; and compared with a traditional process, the method has the advantages of simple raw materials, less generation of three wastes, green environmental protection, fewer side reactions, low cost and the like, and is easy to industrialize.

The present invention provides processes for preparing silanylamines, such as disilanylamines and polysilanylamines, and compositions comprising the silanylamines. In one embodiment, the present invention provides processes for preparing a silanylamine compound, the processes comprising reacting a starting compound of general formula RR.sup.1N(Si.sub.xH.sub.2x+1) with an amine compound of general formula R.sup.2R.sup.3NH to produce the silanylamine compound of general formula R.sup.2.sub.mR.sup.3.sub.n-N(Si.sub.xH.sub.2+1).sub.3-m-n.

Solid or liquid NH free, C-free, and Si-rich perhydropolysilazane compositions comprising units having the following formula [N(SiH.sub.3).sub.x(SiH.sub.2-).sub.y], wherein x=0, 1, or 2 and y=0, 1, or 2 when x+y=2; and x=0, 1 or 2 and y=1, 2, or 3 when x+y=3 are disclosed. Also disclosed are synthesis methods and applications for the same.

Solid or liquid NH free, C-free, and Si-rich perhydropolysilazane compositions comprising units having the following formula [N(SiH.sub.3).sub.x(SiH.sub.2-).sub.y], wherein x=0, 1, or 2 and y=0, 1, or 2 when x+y=2; and x=0, 1 or 2 and y=1, 2, or 3 when x+y=3 are disclosed. Also disclosed are synthesis methods and applications for the same.

An economical method for recovering phosphate or phosphate and nitrogen from liquid streams. A liquid containing phosphate is introduced into a culture of autotrophic microorganisms in the presence of natural or artificial light, thereby producing a liquid effluent with elevated pH and reduced alkalinity. The alkalinity is reduced through the consumption of bicarbonate/carbonate by the autotrophic microorganisms. The effluent is then chemically treated with low-cost chemicals to provide Ca.sup.++ or Mg.sup.++ ions necessary to form a phosphate precipitate such as calcium phosphate or magnesium-ammonium-phosphate (MAP). The autotrophic microorganisms can be cultivated in ponds, lagoons, or photobioreactors. The pH of the culture is adjustable within a preferred range of 7.5 to 10.5 by adjusting the photobioreactor operation. The process includes an economical flotation separator for solid, liquid, gas separation and a means of concentrating ammonia nitrogen that may also be removed during the process of phosphate reclamation.

An economical method for recovering phosphate or phosphate and nitrogen from liquid streams. A liquid containing phosphate is introduced into a culture of autotrophic microorganisms in the presence of natural or artificial light, thereby producing a liquid effluent with elevated pH and reduced alkalinity. The alkalinity is reduced through the consumption of bicarbonate/carbonate by the autotrophic microorganisms. The effluent is then chemically treated with low-cost chemicals to provide Ca.sup.++ or Mg.sup.++ ions necessary to form a phosphate precipitate such as calcium phosphate or magnesium-ammonium-phosphate (MAP). The autotrophic microorganisms can be cultivated in ponds, lagoons, or photobioreactors. The pH of the culture is adjustable within a preferred range of 7.5 to 10.5 by adjusting the photobioreactor operation. The process includes an economical flotation separator for solid, liquid, gas separation and a means of concentrating ammonia nitrogen that may also be removed during the process of phosphate reclamation.

Mono-substituted TSA precursor Si-containing film forming compositions are disclosed. The precursors have the formula: (SiH.sub.3).sub.2NSiH.sub.2X, wherein X is selected from a halogen atom; an isocyanato group; an amino group; an N-containing C.sub.4-C.sub.10 saturated or unsaturated heterocycle; or an alkoxy group. Methods for forming the Si-containing film using the disclosed mono-substituted TSA precursor are also disclosed.

Mono-substituted TSA precursor Si-containing film forming compositions are disclosed. The precursors have the formula: (SiH.sub.3).sub.2NSiH.sub.2X, wherein X is selected from a halogen atom; an isocyanato group; an amino group; an N-containing C.sub.4-C.sub.10 saturated or unsaturated heterocycle; or an alkoxy group. Methods for forming the Si-containing film using the disclosed mono-substituted TSA precursor are also disclosed.