Patent ID: 6936229
Filing Date: 2005-08-30
Classification: C01D,C01F,C01P,C22B,Y02P

Abstract:
1. An apparatus for continuously purifying lithium carbonate comprising: a dissolver which is a baffled reactor to dissolve lithium carbonate that includes a mixer/disperser, a carbon dioxide gas dispersion tube, a wash water filtrate/mother liquor filtrate recycle line, a cooler, a stilling well to separate gas and undissolved lithium carbonate solids from the resultant lithium bicarbonate solution, and a continuous chemical grade lithium carbonate crystal feeder; an inline filter to remove insoluble impurities from the lithium bicarbonate solution coming from the stilling well; a heat exchanger to recover heat from the hot mother liquor that is recycled to the dissolver; a heated gas sealed crystallizer with mixer to decompose the lithium bicarbonate solution to form low sodium lithium carbonate crystals, carbon dioxide gas, and mother liquor; a slurry valve to remove the low sodium lithium carbonate crystals and mother liquor from the gas sealed crystallizer; a gas line to continuously return the carbon dioxide produced in the crystallizer to the dissolver; a separator such as a continuous belt filter to separate the low sodium lithium carbonate from the mother liquor and a wash water section to wash the lithium carbonate crystals; a pump and line to return the mother liquor and wash filtrate to the dissolver; a mother liquor bleed to control the sodium level and to maintain a constant liquid volume; a carbon dioxide make up source.