Flash drying

The burning of the ligneous portion of the black Hquor produces sufficient heat in the furnace to sustain flash drying of residual moisture, salt-cake reduction, and chemical smelting. The heat in the gas passing through the furnace, boiler, and economi2er produces steam for power and process. 

The floated mica concentrate is dewatered. After dewatering (qv), the mica is either dried in a fluid-bed rotary drier, flash dried in a fluid energy mill, or sold "drip-dry" to other mica grinders. The dry mica is then ground and screened to a si2e gradation dictated by the customer. 

Tricalcium Phosphate. Commercial tricalcium phosphate (TCP) is actually an amorphous basic calcium phosphate close to hydroxyapatite in composition. Because of its extremely low solubiUty in water, TCP is precipitated almost quantitatively from dilute phosphate solutions with a slurry of hydrated lime. TCP is separated by dmm-, spray-, or flash-drying the TCP slurry, with or without intermediate sedimentation or filtration steps. It is used as an industrial-grade flow conditioner and parting agent. 

The AIF. solution is filtered, AIF. precipitated by heating, flash dried, and calcined. 

There is some beneficiation of talc by froth flotation (qv), practiced especially on ultramafic-type deposits. In this process (Fig. 2), talc is milled to its hberation size (—100 mesh (ca 0.15 mm)) using ball mills or ring-type roUer mills and then slurried at 10—30% in water. Flotation is done in conventional multistage float cells using methyl amyl alcohol as a frother. Typically two to four stages are required to upgrade the ore from 50—70% talc to 90—98%. The product is filtered and then flash-dried and milled to a final product. 

TABLE 12-33 Sizes and Capacities of ABB-Raymond Cage-Mill Flash-Drying Systems ... 

Atmospheric flash drying, in bar soap manufacture, 22 750-751 Atmospheric fluorine, detection of,... 

Loras, V. (1968). Bleaching and stabilizing of flash-dried mechanical pulp. Pulp and Paper Magazine of Canada, 69(2), 57-63. 

Dehydration. The removal of all (stand-alone) water from a material by one of the following mechanical processes—heating, adsorption, absorption, centrifugal force, condensation, or flash drying. 

This is a process for reducing the water content of sludge by heating. Flash drying, spray drying, rotary kiln drying, or multiple hearth drying can be used. 

The aluminium content of the two samples is comparable, when referred to the silica content of the original clay, and the two PILC have comparable surface areas after calcination at 300°C. The ACH bentonite was formed into small extrudates and flash-dried, whereas sample G5 was dried in a thin cake. In both cases, crushing to a fine powder was easy. Sample G5 retains a higher surface area at 800°C in spite of a higher potassium content. Therefore the K O content of the PILC is not the predominant factor for the thermal stability. 

Drying. Liquid base soap is dried from a 30% water liquid form to a solid of about 15% water content. If desired, some minor ingredients may be blended into the soap stream prior to drying. Methods of drying used m common practice are (1) chip drying, (2) atmospheric flash drying, and (3) vacuum flash drying. 

Vacuum Flash Drying. In this most recent technique, drying takes place m a vacuum vessel similar to an atmospheric tower but smaller. The soap is similarly heated before flashing but under less pressure, so that boiling (actually drying of the soap) occurs in the heat exchangers. Since there is boiling in the heaters, the moisture of the dried soap depends primarily upon soap flow rate, soap pressure, and steam pressure to the heater and to a minor extent on the absolute pressure in the vacuum chamber The final temperature of the soap depends entirely upon the absolute pressure m the vacuum chamber. 

Floating-Bar Manufacture. Base soap made from the desired blends of fat and oil first is flash-dried to a moisture content of about 22%. It then enters a mechanical mixer called a crutcher, where it is thoroughly mixed with perfume, preservatives, and air. The amount of air controls the density of the final product, giving the bar a density of less than one and making it floatable. 

After the preform had been felted from a water slurry, it was compacted at atmospheric pressure, removed from the die dried at 140°F in a steam-heated, circulating air oven. The dried preform was then soaked in the impregnating resin soln, drained, and finally flash-dried in a vacuum oven to a point where it could be post formed... 

In calculating starch and water quantities, adjustments need to be made for the water content of starch, which ranges from 10% to 12% for com starch to 15-18% for potato starch. Starch solids in the slurry may fluctuate if the delivered product is not uniform. The bulk density of the starch will vary depending on the method of drying. Flash dried starch has a bulk density of about 608 kg/m3, while belt dried starch has a bulk density of about 672 kg/m3. 

Flash drying Wet feed is dispersed and conveyed in high velocity stream of hot gas and dries almost instantaneously to granular product. Pneumatic conveying drying Flash dryers, conveying systems... 

Flash drying Drying and granulation of clays, diatomaceous earths ... 

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