Silicates wetting

Sodium silicate wetting, emulsifying, penetrating, and other surface-active properties do not appear to impact ink removal efficiency in flotation (36). Flotation can also remove some of the paper filler and coating particles dispersed in the pulp. Addition of certain cationic oiganic polymers such as poly(dia11yldimethylammonium chloride) to pulp improves the removal efficiency of these particles during flotation (37,38). 

The use of modern analytical instruments has greatly expanded the analyst s ability to determine impurities in silicates. Wet chemical methods usually are far too tedious, suffer from substantial interference or are not sensitive enough for impurity analysis. Even some instrumental techniques are subject to interferences, requiring separation to be used in the analytical procedure. The analyst must also decide on the sensitivity required since lowering detection limits usually increases the cost of analysis and the sophistication of the analytical procedure. 

BARIUM SULLATE PIGMENT ALUMINUM SILICATES DIATOMACEOUS SILICA MAGNESIUM SILICATES WET GROUND MICAS PURE TOLUIDINE RED TONER BARIUM SULFATE PIGMENT MAGNESIUM SILICATE PIGM. ALUMINUM SILICATE PIGM. DIATOMACEOUS SILICA RAW AND BURNT UMBER RAW AND BURNT SIENNA YELLOW IRON OXIDE SYNTHETIC FE-OXIDE INDIAN LACS PINE OIL TALL OIL... 

For waterproofing, sodium silicate concentrations below 30% are adequate concentrations between 35 and 70% are used for strength improvement. Grouts having 35 vol % or higher silicate resist deterioration on freeze—thaw or wet—dry cycles. Water permeability of sands can be reduced from 10 to 10 cm/s. Unconfined compressive strengths of stabilized sand can vary from 103 to 4130 kPa (15—600 psi) the normal range is between 690 and 1380 kPa. 

Calcium Silicate Brick. Sand—lime brick is used ia masonry ia the same way as common clay brick. The bricks, molded from a wet mixture of sand and high calcium hydrated lime, are heated under pressure ia a steam atmosphere. Complex hydrosiUcates are formed that give the bricks high dimensional stabiUty (6). 

A great variety of aluminium-silicate bearing rocks, plastic when wet, hard when dry. Used in pottery, stoneware, tile, bricks, cements, fillers and abrasives. Kaolin is one type of clay. Some clay deposits may include appreciable amounts of quartz. Commercial grades of clays may contain up to 20% quartz. 

Alternatively, as described in U.S. Patent 3,341,557, 6-dehydro-17-methyltestosterone may be used as the starting material. A mixture of 0.4 g of cuprous chloride, 20 ml of 4 M methylmagnesium bromide in ether and 60 ml of redistilled tetrahydrofuran was stirred and cooled in an ice bath during the addition of a mixture of 2.0 g of 6-dehydro-l 7-methyl-testosterone, 60 ml of redistilled tetrahydrofuran and 0.2 g of cuprous chloride. The ice bath was removed and stirring was continued for four hours. Ice and water were then carefully added, the solution acidified with 3N hydrochloric acid and extracted several times with ether. The combined ether extracts were washed with a brine-sodium carbonate solution, brine and then dried over anhydrous magnesium sulfate, filtered and then poured over a 75-g column of magnesium silicate (Florisil) packed wet with hexanes (Skellysolve B). The column was eluted with 250 ml of hexanes, 0.5 liter of 2% acetone, two liters of 4% acetone and 3.5 liters of 6% acetone in hexanes. 

Clay. This material is found at the surface of the earth and often is the major component of soils. The material is plastic when wetted, but becomes hard and brittle when dried and heated. It is composed mainly of hydrous aluminum silicates as well as other minerals. 

In general, greatly reduced rates of attack are observed for impure or dilute nickel alloys compared with pure nickel when exposed to SO2 + O2 atmospheres. Haflan et al. have attributed this to the segregation of impurities at the sulphide/oxide interface causing breakup of the sulphide network. For example in the case of silicon additions, it has been shown that silicates form and it has been proposed that these alter the wetting characteristics of the sulphide and prevent the establishment of an interconnected sulphide network. 

Silica gel can be made by reacting an acid with sodium silicate, which is sold in drug stores as water glass or egg keep, and is used to paint eggs to seal them from air and prevent spoilage. Drying the resulting gel will get the desiccant, or it can be used wet in toothpastes. 

Finely divided solid particles that are wetted to some degree by both oil and water can also act as emulsifying agents. This results from the fact that they can form a particulate film around dispersed droplets, preventing coalescence. Powders that are wetted preferentially by water form O/W emulsions, whereas those more easily wetted by oil form W/O emulsions. The compounds most frequently used in pharmacy are colloidal clays, such as bentonite (aluminum silicate) and veegum (magnesium aluminum silicate). These compounds tend to be adsorbed at the interface and also increase the viscosity of the aqueous phase. They are frequently used in conjunction with a surfactant for external purposes, such as lotions or creams. 

Table 8.9 shows an analysis of a silicate rock and compares the precision of X-ray fluorescence analysis with wet chemical methods and arc/spark emission spectrometry. 

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