Pamela S Watson

US Patent:

51964015, Mar 23, 1993

Filed:

Jul 18, 1990

Appl. No.:

7/553510

Inventors:

William H. Engelmann - Henderson NV
Pamela J. Watson - Inver Grove Heights MN
Sanaa E. Khalafalla - Minneapolis MN
John E. Pahlman - Bloomington MN
Patrick A. Tuzinski - Minneapolis MN

Assignee:

The United State of America as represented by the Secretary of the
Interior - Washington DC

International Classification:

C09K 702

US Classification:

507120

Abstract:

A method of enhancing the fragmentation and excavation of hard, solid materials such as rock formations is provided which comprises adding to the rock surface an aqueous solution including a high molecular weight nonionic polymer such as polyethylene oxide which is capable of hydrogen bonding with water to produce charge-neutralizing positive charge dipoles. The nonionic polymeric solution is thus capable of neutralizing the rock surface charge and obtaining a condition of zero surface charge (ZSC) so that the drilling, tunneling, cutting or other similar operation can be conducted with substantial increases in drilling performance and penetration rate. The method is also extremely effective in extending the lives of drill bits, cutting tools, grinding media, or other polishing or drilling tools such that an enormous savings in terms of replacing equipment can be achieved. The method of the present invention is particularly advantageous in that the nonionic polymer solutions of the invention are effective over a wide range of concentrations in neutralizing the rock surface charge, which has not been the case with previously used methods involving cationic compounds which were only effective at very specific concentrations. The method of the present invention provides a means for enhancing performance and achieving substantial cost savings in a wide variety of drilling, tunneling, cutting and other similar operations.