GENEVA, March 8 -- GUILIN GRIND-ACADEMY MATERIAL TECHNOLOGY CO., LTD. (No. 8 Chuangxin Road, Qixing DistrictGuilin, Guangxi 541004), 桂林磨院材料科技有限公司 (中国广西壮族自治区桂林市七星区创新道8号), GUILIN CHAMPION UNION DIAMOND CO., LTD. (No. 8 Chuangxin Road, Qixing DistrictGuilin, Guangxi 541004), 桂林创源金刚石有限公司 (中国广西壮族自治区桂林市七星区创新道8号) filed a patent ...