A process for electrochemically bleaching pulp which comprises dispersing a pulp in a solution of sodium chloride to provide a first pulp slurry; subjecting said pulp slurry to electrolysis at a pH in the range of about 0 to 2.0; filtering said pulp slurry to remove said pulp; dispersing said pulp in a second solution of sodium chloride to provide a second pulp slurry; subjecting said second pulp slurry to electrolysis at a pH greater than 8.0; and recovering said pulp.
This invention provides a process for treating chemical woodpulp, or chemical cellulose including cotton linter, including the step of applying an electron processing technology (EPT) step to chemical woodpulp, or chemical cellulose, as the case may be, on an in-line basis to provide control of pulp viscosity or degree of polymerization (DP). The invention also provides a method of process control in treating the aforementioned woodpulp or cellulose, including the step of using radiation dose-viscosity relationship curve for applying an EPT step on an in-line basis. The in-line EPT step may, in one form of the invention, replace and hence eliminate a chemical DP reduction step.
System for the electrochemical cleavage of compounds which includes a mediator which has no metals or heavy metals and at least two electrodes for the electrochemical activation of the mediator.
Disclosed are methods for preparing high purity lithium carbonate which can be used for pharmaceutical applications, electronic grade crystals of lithium or to prepare battery-grade lithium metal. Lithium carbonate as commercially produced from mineral extraction, lithium-containing brines or sea water, in aqueous solution is used as a feedstock and reacted with carbon dioxide under pressure to form dissolved lithium bicarbonate. Impurities in the lithium carbonate feedstock are either solubilized or precipitated out. Dissolved impurities are physically separated from the lithium bicarbonate using an ion selective means, such as an ion exchange material, or by liquid--liquid extraction. Purified lithium carbonate is then precipitated.