Mark J Ziegler

US Patent:

8235313, Aug 7, 2012

Filed:

Sep 10, 2009

Appl. No.:

12/556737

Inventors:

Mark J. Ziegler - Rockford IL, US

Assignee:

Unimin Corporation - New Canaan CT

International Classification:

B02C 19/06

US Classification:

241 5, 241 29, 241 40

Abstract:

A method of making frac sand having a selected grade from a naturally occurring, mined sand having a SiOcontent of at least about 80 percent and having a particle size range where the maximum particle size is less than about 8. 0 mm, comprising: crushing the mined sand into an intermediate particulate material; screening the particulate material into a feedstock with particles having a particle size coarser than about 350 mesh and initial values for roundness and sphericity of the particles; passing the particles of the feedstock through a blast tube with an outlet to pneumatically abrade the particles and propel the feedstock in a stream under a given pressure from the outlet; directing the pressurized stream against a fixed target located at a given distance from said outlet to physically abrade the particles to form an output mass containing abraded particles: and, repeating operations (c) and (d) a number of times or process stages until the particles resulting from the repeatedly abraded output mass is a final output mass having both processed roundness and sphericity values of at least 0. 6 and wherein the values are greater than the initial values of the feedstock by at least about 0. 10 to 0. 50.

US Patent:

8464969, Jun 18, 2013

Filed:

Aug 3, 2011

Appl. No.:

13/197520

Inventors:

Mark J. Ziegler - Rockford IL, US

Assignee:

Unimin Corporation - New Canaan CT

International Classification:

B02C 19/06

US Classification:

241 5, 241 26, 241 40, 241284

Abstract:

A method of making frac sand having a selected grade from a naturally occurring, mined sand having a SiOcontent of at least about 80 percent and having a particle size range where the maximum particle size is less than about 8. 0 mm, comprising: crushing the mined sand into an intermediate particulate material; screening the particulate material into a feedstock with particles having a particle size coarser than about 350 mesh and initial values for roundness and sphericity of the particles; passing the particles of the feedstock through a blast tube with an outlet to pneumatically abrade the particles and propel the feedstock in a stream under a given pressure from the outlet; directing the pressurized stream against a fixed target located at a given distance from said outlet to physically abrade the particles to form an output mass containing abraded particles: and, repeating operations (c) and (d) a number of times or process stages until the particles resulting from the repeatedly abraded output mass is a final output mass having both processed roundness and sphericity values of at least 0. 6 and wherein the values are greater than the initial values of the feedstock by at least about 0. 10 to 0. 50.