PROCESS FOR PRODUCING ANHYDROUS SODIUM CHLORIDE AND PURIFIED SATURATED BRINE

• US 3,655,333 A
• Filed: 05/04/1970
• Issued: 04/11/1972
• Est. Priority Date: 05/04/1970
• Status: Expired due to Term

• Current Assignee: Vernon A. Stenger, Walter R. Kramer
• Original Assignee: Vernon A. Stenger, Walter R. Kramer
• Inventors: Stenger, Vernon A., Kramer, Walter R.
• Primary Examiner(s): Stern, Edward
• Application Number:
  US05/034,420
• Time in Patent Office: 708 Days
• Field of Search: 23/89,42,40,39,38,303
• US Class Current: 62/537
• CPC Class Codes: C01D 3/06 Preparation by working up brines; seawater or spent lyes

Abstract

Solid sodium chloride is incorporated into a sodium chloridesaturated brine containing dissolved matter, other than sodium chloride, to be concentrated. The temperature of the system is reduced to within the range from about 0* C. to about -21* C. to form sodium chloride dihydrate. The dihydrate is separated from the aqueous system thereby increasing the concentration of the other dissolved matter relative to the remaining liquid phase. The process is particularly useful for concentrating dilute systems for further treatment or ultimate disposal.

Claims

2. A method as in claim 1 wherein the process steps are applied a second time to the aqueous phase separated from the sodium chloride dihydrate.

3. A method as in claim 1 wherein the saturated brine is prepared from a waste stream containing, in addition to the dissolved organic or inorganic contaminants to be concentrated, less than a saturating amount of NaCl and sufficient additional NaCl is first added to the brine to saturate it with NaCl.

4. A method as in claim 1 wherein decomposition of the dihydrate is achieved by heat exchanging it with incoming crude brine.

5. A method as in claim 1 wherein the solid sodium chloride incorporated into the brine is a crude salt.

6. A method as in claim 1 wherein the suspension of solid salt in brine is controlled to a temperature within the range from bout -5* to about -15* C.