Spodumene

Corning 9608 P-spodumene soHd solution, Li,0-Al2 03-(Si0J j low expansion, high chemical durabiHty cooking utensils... 

Corning 9617 P-spodumene soHd solution anatase, Ti02 low expansion, high strength, thermal StabiHty, chemical durabiHty electric range tops (opaque)... 

Corning 0330 P-spodumene soHd solution mtile HO2 mechanical, chemical, thermal stabiHty exterior, interior cladding, laboratory bench tops... 

Coming 9455 P-spodumene soHd solution mullite, 3 A12 02-2 Si02 low expansion, high thermal and mechanical stabiHty heat exchangers... 

Neoceram (Japan) P-spodumene low expansion cooking ware... 

Fig. 2. RepHca electron micrograph of the fracture surface of enstatite—P-spodumene—zirconia glass-ceramic, showing twinning in the enstatite grains...

PetaHte, also a monoclinic lithium aluminum siHcate, LiAlSi O Q, has a theoretical Li O content of 4.88%. Commercial ores usually contain 3.5—4.5% Li O without concentration and ate a preferred source of lithia for use in ceramics and specialty gla2es. PetaHte is monoclinic and has a density of 2.4—2.5 g/cm. Heating to high temperature results in an irreversible phase change to a P-spodumene—Si02 soHd solution that could provide an extractable source... 

Recovery from Ores and Clays. The preferred method of extraction of lithium from spodumene ore is the sulfuric acid process (18), used on ore concentrates of 5—6% Li O, representing 62—74% pure spodumene. Methods suitable for extraction from spodumene also can be used for petaUte, because the latter mineral converts to P-spodumene—Si02 soHd solution on heating to a high temperature. 

One ion-exchange process, which was used for several years by Quebec Lithium Corp., is based on the reaction of P-spodumene with an aqueous sodium carbonate solution in an autoclave at 190—250°C (21). A slurry of lithium carbonate and ore residue results, and is cooled and treated with carbon dioxide to solubilize the lithium carbonate as the bicarbonate. The ore residue is separated by filtration. The filtrate is heated to drive off carbon dioxide resulting in the precipitation of the normal carbonate. 

There has been much interest in making chemicals from brine because of the low expense compared to alternative methods. Lithium, for example, had been mostly produced from spodumene ore, but now most is produced from brine. Those now producing from ore are seriously researching brine reserves and contemplating converting to brine sources before the turn of the century. Similady, solar salt has cost advantages over mined rock salt. Potassium chloride produced from brine has more than doubled from 1980 to 1990. 

Manufacture. Calcined spodumene [1302-37-0], a lithium aluminum sihcate, LiAlSi O, is treated with sulfuric acid, neutralized to pH 6, and... 

Spodumcnc. A mixture of quartz, feldspar, and spodumene is being calcined in rotary kilns at 1475 K to produce lithium aluminum silicate. 

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