Dried silicate solutions powders

Mr. Eowbottom produces borax dry soap, soap powder by adding borax to the usual carbonate or silicated ash or alkali, or other substance used in the manufacture of dry or powder soaps. For hcrtu mft Maps he adds a solution of borax to the ingredients usually employed for making ordinary soft soaps before or during the manu ctore, or he dissolves by heat any ordinary soft soap in the borax solution, and incorporates the same, after which the mass is allowed to cool in the usual maimer. 

Hydrous sodium polysilicate powders are manufactured by removing a part of the water content of the corresponding silicate solutions through drum or spray drying (see Table 22.1) [1,7,8,17-19,21,49]. 

During the process, the aqueous silicate solution is introduced into the upper portion of the gas-fired spray dryer and passes through a spray nozzle or a disk atomizer (see Figure 22.5). The speed of the spray wheel may be about 11,000 rpm. The finely and evenly dispersed liquid comes into contact with upwardly directed hot air. Typical spray tower tanperatures are about 180°C [21] with inlet temperatures of about 260-300°C and outlet air temperatures of above lOO C. The resultant spray-dried droplets adopt the form of hollow microspheres. The silicate particles are collected at the spray dryer s bottom and are withdrawn by a screw conveyor. The amorphous sodium silicate may have a bulk density on the order of 250-500 g/L, an SiOjiNajO molar ratio of 2.04 1, and an ignition loss on the order of 19-20%. Its mean particle size can be on the order of 100-200 pm. The material may be subjected to further milling to modify the form and density of the powder [51,63]. 

Data per 1 t of Product Sodium Silicate Furnace Lumps Sodium Silicate Furnace Liquor Hydrothermal Sodium Silicate Solution Spray-Dried Sodium Silicate Powder" Sodium Metasilicate Pentahydrate Layered Sodium Disilicate ... 

Silicagel R (Reanal, Hungary, analytical grade), silica powder (precipitated from commercial sodium silicate solution by alcohol and then dried and sieved. The Na content at the surface of the precipitated silica was 3.07 mmol per 100 g solid powder, determined poten-tiometrically.), silicates Sepiolite (Spain), Zeolite 13X (Linde, FRG), kaolinite (Zettlitz, FRG), illite (Fiizerrad-vany, Hungary), montmorillonite (Mad, Hungary), and vermiculite (South Africa). The specific surface areas of the adsorbents are summarized in Table 1. Their detailed description has been published [23—26]. 

ABHERENT. Any substance that prevents adhesion of a material to itself or to another material. It may be in the form of a dry powder (a silicate such as talc, mica, or diatomaceous earth) a suspension (bentonite-water) a solution (soap-water) or a soft solid (stearic acid, tallow waxes). Abherents are used as dusting agents and mold washes in the adhesives, rubber, and plastics industries. Fats and oils are used as abherents in the baking industry. Fluorocarbon resin coatings on metals are widely used on cooking utensils. 

Al203, are dissolved in 2,300 ml of water, to which a solution comprising 272 g of caustic soda with 800 ml of water, is slowly added with stirring. Thereafter, a solution comprising 414 g of sodium silicate (Na20, 9%, Si02, 29%) with 100 ml of water is added, the mixture is heated and is stirred for five hours, while keeping the temperature at 60°C. When the reaction mixture becomes neutral it is allowed to cool and to stand, the supernatant fluid is withdrawn and the white gel-like precipitate is washed by decantation to remove the impurities and dried at 105°-110°C and 350 g of white powder of fine particle size is obtained as the final product (almasilate). 

Silicates. Both sodium and potassium silicate solids or solutions have valued functionality including emulsification, buffering, deflocculation, and antiredeposition ability. Silicates also provide corrosion protection to metal parts in washing machines, as well as to the surfaces of china patterns and metal utensils in automatic dishwashers. Silicates are manufactured in liquid, crystalline, or powdered forms and with different degrees of alkalinity. The alkalinity of the silicate provides buffering capacity in the presence of acidic soils and enhances the sequestration ability of the builder system in the formulation. The sili-cate/alkali ratios of the silicates are selected by the formulator to meet specific product requirements. Silicate ratios of 1/1 are commonly used in dry blending applications with silicate ratios of 2/1 and higher commonly used in laundry and autodish applications. 

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