Sulfur Water Softeners

Uses The highest value inorganic acid marketed in the U.S. and second in value to sulfuric acid. Used primarily for the preparation of salts used as fertilizers (ammonium and calcium salts), water softeners and detergents, animal feeds, and baking powder. Food-grade phosphoric acid is used to acidify soft drinks, e.g.. Coca Cola. Organic phosphates are used in flame retardants. 

Scale prevention methods include operating at low conversion and chemical pretreatment. Acid injection to convert COs to CO2 is commonly used, but cellulosic membranes require operation at pH 4 to 7 to prevent hydrolysis. Sulfuric acid is commonly used at a dosing of 0.24 mg/L while hydrochloric acid is to be avoided to minimize corrosion. Acid addition will precipitate aluminum hydroxide. Water softening upstream of the RO By using lime and sodium zeolites will precipitate calcium and magnesium hydroxides and entrap some silica. Antisealant compounds such as sodium hexametaphosphate, EDTA, and polymers are also commonly added to encapsulate potential precipitants. Oxidant addition precipitates metal oxides for particle removal (converting soluble ferrous Fe ions to insoluble ferric Fe ions). 

Because it is cheap, calcium hydroxide is used in many chemical processes that require a strong base. It is used in the production of sodium hydroxide, ammonia, bleaching powder, and many other chemicals. Calcium hydroxide is also used as an insecticide in the form of lime-sulfur spray, in water softening, and in the production of numerous materials such as stucco and mortar which are widely used in the building construction industries. 

After cleaning to remove coarse material, ie, cobs, and fines (broken com, dust, etc), the com is steeped in a sulfurous acid solution to soften the com and render the starch granules separable from the protein matrix that envelopes them. About 7% of the kernel s dry substance is leached out during this step, forming protein-rich steep-water, a valuable feed ingredient and fermentation adjunct. 

Thiosahcyhc 2Lcid[147-93-3] (o-mercaptobenzoic acid), a sulfur-yeUow sohd that softens at 158°C, has a melting point of 164°C. It sublimes, is slightly soluble in hot water but freely soluble in glacial acetic acid and alcohol, and yields dithiosahcyhc acid [527-89-9] upon exposure to air. 

Trinidad asphalt has a relatively uniform composition of 29% water and gas, 39% bitumen soluble in carbon disulfide, 27% mineral matter on ignition, and 5% bitumen that remains adsorbed on the mineral matter. Refining is essentially a process of dehydration by heating the cmde asphalt to ca 165°C. The refined product averages 36% mineral ash with a penetration at 25°C of about 2 (0.2 mm), a softening point (ring and ball method) of 99°C, a flash point (Cleveland open cup) of 254°C, a sulfur content of 3.3%, and a saponification value of 45 mg KOH/g. The mineral matter typically contains... 

The residue in the Claisen flask can be softened by water and broken up with a rod. The small amount remaining is easily removed with concentrated nitric or, preferably, concentrated sulfuric acid. 

Tests were also run with simulated brackish agricultural drainage water, as illustrated in Table 4. A feedwater composition containing sodium, calcium, chloride, sulfate, and bicarbonate ions was prepared in such a way as to duplicate the water in the Mohawk-Wellton drainage canal at Yuma, Arizona. Salt rejections were relatively poor toward this synthetic feedwater, but when this water was line-softened and acidified to pH 5.5 with sulfuric acid, salt rejection of the 90 10 copolyamide improved markedly. However, the membrane s water flux declined by nearly 50 percent. Salt rejection and flux were found in this and other examples to be markedly dependent on pH. As the pH approached the pKa of... 

Pure hexanitrocarbanilide crystallizes from acetone-ligroin in pale yellow rosettes which soften and darken at 204° and melt at 208-209° with decomposition. It yields picric acid when warmed with dilute sulfuric acid, and trinitroaniline when boiled with strong ammonia water. A deep ruby-red color is developed when hexanitrocarbanilide is allowed to stand at ordinary temperatures in contact with strong ammonia water. Tetranitrocarbanilide, dinitroaniline, trinitroaniline, picric acid, and dinitro-phenol do not give this color. 

All cooling water treatment programs, whether designed in-house or via a water treatment service company, continue to focus on the minimization of hard water crystalline scales and sludges in the system as a major criteria for success. Program techniques employed are either pretreatment processes, such as lime-soda softening or ion exchange, the use of sulfuric acid or polymer-based chemicals that operate in an alkaline environment, or combinations of some or all of these processes. 

Prior to wet-milling, the com must be softened by a steeping process developed specifically to produce optimum milling and separation of com components. Steeping is more than simple water soaking of com. It involves maintaining the correct balance of water flow, temperature, sulfur dioxide concentration and pH. Com is normally steeped for 24-40 hours at a temperature of 48°C to 52°C. By the end of the steeping period, the kernels should have (a) absorbed water to about 45% (wet basis) ... 

CaO(s) + H20w —> Ca(0H)2(aq) Many municipal water treatment plants use calcium hydroxide to soften very hard water before releasing it for public use. Most non-metal oxides react with water to form acidic solutions. For example, sulfur dioxide gas dissolves in water to form sulfurous acid. 

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