Back to results
US 5,569,152 AGranted
Buffering of cementitious hazardous waste compositions containing electric arc furnace dust
AssigneeConversion Systems, Inc.
InventorCharles L. Smith
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeConversion Systems, Inc.
InventorCharles L. Smith
Estimating the term…
A buffering agent for a cementitious hazardous waste composition, containing electric arc furnace dust (EAFD) and water, includes dolomitic lime, namely either dolomitic quicklime, dolomitic monohydrated lime or dolomitic dihydrated lime. Dolomitic lime serves as a buffering agent for the hazardous waste composition by maintaining the pH of the waste composition within a target range over which solubility of several heavy metals tends to be minimized. These heavy metals include lead, zinc and cadmium, among others, and the pH range within which the heavy metals experience a minimum solubility is approximately 8.5 to 11.5, and preferably 9.4 to 10.2. In addition, dolomitic lime is substantially insoluble in water, so that the buffering agent will not leach or diffuse out of the waste composition.
A buffered hazardous waste composition comprising EAFD, sufficient water to react with said EAFD and dolomitic lime in an amount sufficient to:
A method of treating a hazardous waste composition, comprising EAFD and water, to reduce heavy metal ion solubility in water, said method comprising the steps of:
In a method of stabilizing a hazardous waste containing EAFD including forming a mixture of EAFD and water, the improvement comprising including in said mixture a buffering agent comprising dolomitic lime.
Dependencies are inferred from the claim text.