Chlorine sodium silicates

Instead of decomposing sodium chloride with sulphuric acid in order to obtain sodium sulphate, attempts have been made to prepare hydrogen chloride from sodium chloride, leaving a by-product of greater commercial value than sodium sulphate. Some of these processes furnish chlorine—q.v. Most of the proposals have either not been applied at all on an industrial scale, or else have had a very brief industrial life. For example, it has been proposed to heat an intimate mixture of sodium chloride and clay with steam, and to obtain sodium silicate and hydrogen chloride as products of the main reaction. A. Gorgeu13 has shown that clay with about 35 per... 

Silicon carbide is comparatively stable. The only violent reaction occurs when SiC is heated with a mixture of potassium dichromate and lead chromate. Chemical reactions do, however, take place between silicon carbide and a variety of compounds at relatively high temperatures. Sodium silicate attacks SiC above 1300°C, and SiC reacts with calcium and magnesium oxides above 1000°C and with copper oxide at 800°C to form the metal silicide. Silicon carbide decomposes in fused alkalies such as potassium chromate or sodium chromate and in fused borax or cryolite, and reacts with carbon dioxide, hydrogen, air, and steam. Silicon carbide, resistant to chlorine below 700°C, reacts to form carbon and silicon tetrachloride at high temperature. SiC dissociates in molten iron and the silicon reacts with oxides present in the melt, a reaction of use in the metallurgy of iron and steel (qv). The dense, self-bonded type of SiC has good resistance to aluminum up to about 800°C, to bismuth and zinc at 600°C, and to tin up to 400°C a new silicon nitride-bonded type exhibits improved resistance to cryolite. 

If only one run is to be made, good quality corks are satisfactory. If several runs are made, it is recommended that the corks be impregnated with sodium silicate solution to prevent excessive corrosion by the hydrogen chloride and chlorine. 

Compounds %. by Wei ght BASF Surfactant 3 Sodium tripolyphosphate 34 Britesil H24 hydrous sodium silicate 17 Sodium sulfate 15 Sodium carbonate 19 Chlorinated isocyanurate 2 Water 10... 

Corks impregnated with sodium silicate solution resist attack by hydrogen chloride and chlorine. 

Activated silica and clays have also been used as coagulant aids. Activated silica is sodium silicate that has been treated with sulfuric acid, aluminum sulfate, carbon dioxide, or chlorine. When the activated silica is applied, a stable negative sol is produced. This sol unites with the positively charged primary-metal coagulant to produce tougher, denser, and faster settling floes. 

Activated silica—Sodium silicate that has been treated with sulfuric acid, aluminum sulfate, carbon dioxide, or chlorine. 

Nonchloride species are probably rapidly converted to oxides (Na20, K2O) on leaving the flame front. The volatile alkalies may condense on the surfaces of fly-ash particles carried by the flue gas or on cooler boiler surfaces. Wibberly and Wall [j ] performed drop-tube experiments in which silica particles were exposed to synthetic combustion gases containing sodium at temperatures of 1200 to 1600°C. Sodium silicate layers ranging in thickness from 0.03 to 0.3 pm were observed on the particle surfaces, and sintered deposits formed rapidly on stainless steel probes inserted into the lower part of the furnace. Such alkali-silicate layers are molten at the temperatures of interest. The thickness of the sodium silicate layers was decreased by a factor of three when the sodium was introduced in the form of NaCl, rather than in chlorine-free forms. 

Hunan Zhuzhou Chemical Group has approximately 7000 employees. It produces PVC suspension polymerization resin with annual capacity of 30 000 tonnes. The company is the largest production facility for chemical raw materials in South China. The key products of the company are plastic door and window frames, foam core pipe, p-chlorotoluene, o-chlorotoluene, ethylamine, vitriol, PVC, NaOH, liquid chlorine, hydrochloric acid, chloral, F-22, chloroform, fluoride, sodium silicate and hydrofluoric acid. 

The metal chlorides normally used as chlorinating agents are the low-cost reagents sodium chloride and calcium chloride. Silicates, carbonates and sulfates can be chloridized... 

Multimedia filters, which consist of a top layer of coarse and low density anthracite, layers of silica, and then dense finest medium vitreous silicate, remove about 98% of particulates >20 tm. These filters are regularly back-washed to avoid buildup of particulates. Finer filters (S-lO tm) are used to remove suspended matter and colloidal materials. To prevent scaling due to water hardness, sodium ions generated from brine are exchanged with calcium and magnesium ions in the water. Activated carbon or metabisulfite is used to remove chlorine. 

Two inorganic water-soluble polymers, both polyclcctrolytcs in their sodium salt forms, have been know ll for some time poly(phosphoric acid) and poly(silicic acid). A more exciting inorganic water-soluble polymer with nonionic characteristics has been reported. This family of phosphazene polymers is prepared by the ring-opening polymerization of a heterocyclic monomer (6) followed by replacement of the chlorine atoms in Ihe resultant polymer. 

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