Kiln drying

Similar to processing mined rock salt, solar salt may be cmshed, screened, and kiln dried or fluidized-bed dried. Coarse solar salt is a premium product because of high purity and relatively large crystal size. It is in particular demand for use to regenerate the resin in cation-exchange water softeners... 

Table 4. Approximate Air-Drying and Kiln-Drying Periods for 2.5-cm Lumber...

Table 5. Typical Softwood Kiln-Drying Time Schedules for 2.5-cm Ponderosa Common Pine...

Hours in kiln Dry-bulb temperature, °C Wet-bulb temperature, °C Relative humidity, %... 

Kiln-dried to average 12% moisture content in 24—36 h. Kiln-dried to average 12% moisture content in 48—72 h. 

All the properties of wood depend to some extent on the amount of water it contains. Green wood can contain up to 50% water. Seasoning (for 2 to 10 years) or kiln drying (for a few days) reduces this to around 14%. The wood shrinks, and its modulus and... 

Darre,/. drying, kiln-drying drying room or kiln Brewing) malt kiln Metal.) liquation hearth withering. 

For engineered uses the allowable stresses arc slightly lower, for kiln-dried lumber slightly higher. For slion-ienn loads, such as wind, earthquake, or impaci, higher unit stresses arc allowed... 

Another commercial method of preparing a beta dextrose-containing product consists of the spray drying of a hot concentrated dextrose solution. To aid in removing last traces of water the solution is sprayed onto a moving bed of anhydrous solid product, conveniently obtained from a previous batch. The product is finally kiln dried and appears as pellets or pearls containing a mixture of beta and alpha dextrose.19... 

The contamination in beer with NOC was first reported in Germany in 197987. The contamination of beer occurs during the kilning (drying) process of malt88 and fermentation89, which leads to the occurrence of NDMS and NPYR. The nitrogen oxides were identified as a source of nitrosamine formation in the beer, formed by nitrosation of the alkaloids... 

The most important applications of solvent dehydration lie within the field of kiln drying for seasoning timber where substantial reductions in drying times have been achieved150 . 

The process involves an impregnation step (using either a Kebony or VisorWood treatment solution), followed by intermediate drying prior to curing, and final kiln drying (Figure 8.6). 

The phosphate concentration in the tailings is upgraded to a level adequate for commercial exploitation through removal of the nonphosphate sand particles by flotation [32], in which the silica solids are selectively coated with an amine and floated off following a slurry dewatering and sulfuric acid treatment step. The commercial quality, kiln-dried phosphate rock product is sold directly as fertilizer, processed to normal superphosphate or triple superphosphate, or burned in electric furnaces to produce elemental phosphorus or phosphoric acid, as described in Section 9.2. 

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. 

Air-dried wood, with twenty par cent, of hygroscopic moisture, Kiln-dried ten ... 

Kiln-dried wood, without hygroscopic moisture,. 

Kiln-dried turf, with no moisture and fifteen per cent, of asli,. 

Best kiln-dried, turf, without moisture end ash,. 

Kiln-dried fibrous lignite, with twenty per cent, moisture and no ash,. 

Although developed as early as 1888 by the Austrian chemist. Karl Josef Bayer, the Bayer process still is used abnost exclusively for the extraction of alumina from ores, The bauxite first is reacted under pressure with hot caustic, which dissolves the ALO3 xH20 to form sodium aluminate, The solution is filtered hot. then cooled and agitated with the addition of a small quantity of aluminum hydrate to enhance the precipitation of the crystalline hydrate. After filtration, the cake is kiln-dried at 1100 °C to remove H20 and yield A1203... 

Aluminum oxide is produced during the recovery of bauxite, which is crushed, ground, and kiln dried, followed by leaching with sodium hydroxide, forming sodium aluminate, from which alumina trihydrate is precipitated and calcined (Bayer process) (HSDB 1995). 

Kiln-drying does not depend on the weather and, in addition, due to the high temperature used, the wood is essentially sterilized. However, if kiln drying is delayed mould and sapstain fungi may discolor the wood. 

Gerhards (57) reviewed the results of 12 separate studies on strength properties of fire-retardant-treated wood conducted at the FPL and other laboratories. He concluded that modulus of rupture (MOR) is consistently lower and modulus of elasticity (MOE) and work to maximum load are generally lower for fire-retardant-treated wood than for untreated wood if fire-retardant treatment is followed by kiln drying. The effect may be less or negligible if the fire-retardant-treated wood is air dried instead of kiln dried. The most significant loss was in work to maximum load, a measure of shock resistance or brashness, which averaged 34 percent reduction. 

The losses from treating and kiln drying for small clear specimens averaged about 13 percent for MOR and 5 percent for MOE. Losses in structural sizes were about 14 percent for MOR and 1 percent for MOE (57). Losses due to high temperature kiln drying, above 65°C may be considerably greater (58). 

Masson, E., Baumes, R., Moutounet, M., and Puech, J. L. (2000). The effect of kiln drying on the levels of ellagitannins and volatile compounds of European oak (Quercus petraea Liebl.) stave wood. Am. ]. Enol. Vitic. 51, 201-214. 

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