Antifreeze purification
AssigneeEnvirocorp Services & Technology, Inc.
InventorRonnie D. Gordon
Life of this patent
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Abstract
The present invention in one embodiment, is a process that uses a chemical treatment to remove arsenic, organic acids, and heavy metals from antifreeze solutions. In one aspect such a method includes adding an iron salt, to an antifreeze solution containing arsenic and heavy metals with adequate mixing for dispersion throughout the solution. Then, a base is added to increase the pH to a level from about 8 to 10. As the base is added, a precipitate forms and is then removed by standard filtration techniques. The arsenic, organic acids, and heavy metals co-precipitate with the iron and are removed by filtration. The process may either be a batch process or a continuous process.
Claims17
A process for removing arsenic from antifreeze, the process comprising
- introducing arsenic-contaminated antifreeze into a reactor vessel,
- introducing a ferric salt into the antifreeze in the reactor vessel to produce a mixture with antifreeze and arsenic-containing precipitated solids, the mixture having a pH of between about 5 to 7,
- adding a base to the antifreeze and ferric salt to adjust pH to between about 8 and 10 to enhance precipitated solids formation, and
- filtering the reaction mixture to filter out arsenic-containing precipitated solids from antifreeze in the reaction mixture, producing re-useable antifreeze.
A process for removing arsenic from antifreeze, the process comprising
- introducing arsenic-contaminated antifreeze into a reactor vessel,
- introducing a ferric salt into the antifreeze in the reactor vessel to produce a mixture with antifreeze and an arsenic-containing precipitate, the mixture having a pH of between about 5 to 7, a ratio by weight of ferric ion to arsenic ion in the reactor vessel ranges between 100 to 1 and 1 to 1,
- stirring together the ferric salt and antifreeze,
- adding a base to the antifreeze and ferric salt to adjust pH to between about 8 and 10 to enhance precipitated solids formation, the precipitated solids containing arsenic,
- adding a low molecular weight polyacrylate precipitation enhancer to the reactor vessel,
- filtering the reaction mixture to filter out the arsenic-containing precipitated solids from antifreeze in the reaction mixture, producing re-useable antifreeze containing less than five parts per million arsenic by weight.
Dependencies are inferred from the claim text.