US 6,854,809 B1 · Sodium carbonate and sodium bicarbonate production from nahcolitic oil shale

Abstract

A method for solution mining nahcolite, capable of extracting nahcolite from geological formations lean in nahcolite comprising injecting high pressure water (which may include recycled aqueous solution of bicarb and sodium carbonate) at a temperature of at least 250° F. into the formation, dissolving nahcolite in the hot water to form a production solution and recovering the production solution. The invention also includes the processing of the production solution to provide sodium carbonate and, optionally, sodium bicarbonate, comprising: decomposing the sodium bicarbonate portion of the hot aqueous production solution to form a hot aqueous solution of sodium carbonate; evaporating water from the hot aqueous solution comprising sodium carbonate to form a concentrated solution of sodium carbonate; producing sodium carbonate monohydrate from the concentrated solution of sodium carbonate by crystallization; and dewatering and calcining the sodium carbonate monohydrate to produce anhydrous sodium carbonate.

Claims33

Dependent claims

A method for solution mining nahcolite, capable of extracting nahcolite from geological formations containing deposits of lean nahcolitic oil shale as well as beds of essentially pure nahcolite, comprising:

establishing at least one well;
injecting hot aqueous liquid via the well into a mining zone within the formation, so that the hot aqueous liquid has a temperature of at least 250° F. in the mining zone and is maintained at a sufficiently high pressure to prevent flashing of carbon dioxide and water vapor;
dissolving nahcolite in the hot aqueous liquid to form a production solution comprising water and sodium bicarbonate;
and
recovering the production solution from the mining zone through a well.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

10/619,397Filed 14 Jul 2003 · continuation

Priority

8 Jan 1999

Granted

15 Feb 2005

Term ends

Not estimatedThe source records don’t support an estimate.

Classification7 codes

C01D 7/12
Carbonates of sodium, potassium or alkali metals in general: preparation of carbonates from bicarbonates or bicarbonate-containing product
C01D 7/126
Preparation of carbonates from bicarbonates or bicarbonate-containing product: multi-step processes, e.g. from trona to soda ash
C01D 7/35
Carbonates of sodium, potassium or alkali metals in general: varying the content of water of crystallisation or the specific gravity
E21B 43/281
Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent: using heat

Sodium carbonate and sodium bicarbonate production from nahcolitic oil shale

Life of this patent

Sodium carbonate and sodium bicarbonate production from nahcolitic oil shale

Life of this patent

Abstract

Claims33