Spray-calcining

Leaching of Sintered Granules. The initial studies in this work(J3) were done in granules consisting of 80% PW-4b spray-calcined simulated waste, 10% silica, and 10% borosilicate glass frit sintered at 1100 C. The granules were about 0.6 cm in diameter and weighed about 370 mg each. The surface area, based on the assumption of an impervious hard") spherical shape,... 

When the objective is to prepare an extremely intimate mixture of two or more different oxides, each of them constituted of very small grains or particles, techniques such as spray calcination, oil drop, or freeze drying, the complcxation methods (and generally all methods described in Sections B and C above) and the sol-gel method seem to have the same potential in principle. The... 

Developed at BNL) Spray-calciner melter (Developed at Hanford)... 

U.S. vitrification processes. In the United States [M2] development efforts are focused on two processes, a spray-calcine/in-can melting process and a ceramic melter process that may be... 

In the spray calciner, liquid waste is pumped to a nozzle at the top of the calciner where it is atomized by pressurized air, producing droplets with diameters less than 70 irni that are dried and calcined in-fli t in the 700 C-wall-temperature spray chamber. Sintered stainless steel dust filters collect a portion of the powder with a mean diameter of 10 fjm. They are periodically cleaned by a reverse pulse of air. Calcine from the spray chambers and filters drops directly into the melting canister. Frit is fed to the cone of the calciner. 

Figure 11.11 Spray calciner/in-can melter. Courtesy of Battelle Pacific Northwest Laboratories.)...

A spray calciner designed for a 5 MT/day reprocessing plant has an incoming waste flow rate of 118 liters/h with 75 g/liter solids to be combined with an off-gas system recycle of 8 liter/h to a total calciner feed of 126 liter/h with 70 g/liter solids. The product stream is 15.6 kg/h calcined solids. The demand on atomizing air is 0.85 m /min. 

Spray calciner/in-can-melter (U.S.-Battelle PNL) Borosilicate glass Monolithic cylinder Furnace-heated canister Spray calcine Thermal... 

Ceramic melter (U.S.-Battelle PNL) Fluidized-bed calciner (U.S.— INEL, Idaho Falls) Borosilicate glass Calcine MonoUthic cylinder Granules (for disposal to be consolidated) Joule-heated ceramic Spray calcine or liquid Thermal Thermal (incomplete)... 

The wiped-film evaporator is a special type of evaporator that permits evaporation to a much higher concentration of solids than do other evaporators. Liquid is fed into a heated cylinder that contains rotating blades or wipers to reduce the liquid to a film, thereby improving the heat-transfer efficiency. Wiped-film evaporators can also be operated as dryers. Other equipment that can be used for drying and calcining non-high-level waste is the same as for HLW, e.g., spray calciners, fiuidized-bed calciners, and rotary kilns. 

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