Accelerating agents for accelerating hardening of cement

• US 4,257,814 A
• Filed: 06/26/1979
• Issued: 03/24/1981
• Est. Priority Date: 05/10/1977
• Status: Expired due to Term

• Current Assignee: Coal Industry (Patents) Limited
• Original Assignee: Coal Industry (Patents) Limited
• Inventors: Mills, Peter S., Kellet, William H.
• Primary Examiner(s): Poer, James
• Application Number:
  US06/052,142
• Time in Patent Office: 637 Days
• Field of Search: 106/90, 106/97, 106/104, 106/315, 299/11, 405/266, 405/267
• US Class Current: 106/718
• CPC Class Codes: C04B 14/104 Bentonite, e.g. montmorillonite
• CPC Class Codes: C04B 18/12 from quarries, mining or the like
• CPC Class Codes: C04B 2103/12 Set accelerators
• CPC Class Codes: C04B 2111/00724 in mining operations, e.g. for backfilling; in making tunnels or galleries
• CPC Class Codes: C04B 22/10 containing carbon in the anion
• CPC Class Codes: C04B 24/122 Hydroxy amines
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 40/0658 Retarder inhibited mortars activated by the addition of accelerators or retarder-neutralising agents
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete

Abstract

An agent for accelerating hardening of cement for use in an underground mining installation employing concrete-like packs including run-of-mine coal. The agent comprises by weight one and a half parts triethanolamine, five parts sodium carbonate and one part potassium carbonate. Too rapid setting of quick setting cement is avoided by the agent because a slurry of cement in water is mixed with a slurry of agent and run-of-mine coal in bentonite in a mixer immediately before being added to a pack so that setting cement does not occur in pipes leading to the mixer.

Claims

1. A method of at least partially filling a cavity in an underground mine which method comprises the steps of

(a) where required, defining said cavity using shuttering,

(b) charging to said cavity a first aqueous slurry containing a hydraulic cement and concurrently charging and mixing with said first aqueous slurry a second aqueous slurry containing an agent for accelerating hardening of the hydraulic cement and

(c) permitting the mixed slurries to harden into a supportive concrete-like material in the cavity.

2. A method as claimed in claim 1, wherein the second slurry contains a dirt aggregate.

3. A method as claimed in claim 1, wherein the first slurry contains a dirt aggregate.

4. A method as claimed in claim 2, wherein the dirt aggregate comprises run-of-mine coal.

5. A method as claimed in claim 1 wherein the agent comprises triethanolamine and at least one alkali metal carbonate.

6. A method as claimed in claim 5, wherein the agent comprises triethanolamine, sodium carbonate and potassium carbonate.

7. A method as claimed in claim 6 wherein the agent comprises by weight one and a half part triethanolamine, five parts sodium carbonate and one part potassium carbonate.