Patent AU-2019316539-B2 (AU)
Title: Improvement of geotechnical characteristics of tailings via lime addition
Inventor: LEIKAM JARED IRA
IPC: C02F1/00
Filed: 2019-09-10
Granted: 2021-04-01
Abstract: INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) 
(19) World Intellectual Property 
(1) Organization11111111111111111111111I1111111111111i1111liiili 
International Bureau (10) International Publication Number 
(43) International Publication Date W O 2020/055893 Al 
19 March 2020 (19.03.2020) W IPO I PCT 
(51) International Patent Classification: Wayne; c/o Graymont Western Canada Inc., 200-10991 
C1OG 1/04 (2006.01) C02F1/52 (2006.01) Shellbridge Way, Richmond, British Columbia, V6X 3C6 
C02F11/145(2019.01) C02F1/56(2006.01) (CA).TATE,Michael,John;c/oGraymontWesternCana
(21) International Application Number: da Inc., 200-10991 Shellbridge Way, Richmond, British 
Co
PCT/US2019/050448 lumbia, V6X 3 C6 (CA). HARIHARAN, Narain; c/o Gray
mont Western Canada Inc., 200-10991 Shellbridge Way, 
(22) International Filing Date: Richmond, British Columbia, V6X 3C6 (CA). LEIKAM, 
10 September 2019 (10.09.2019) Jared, Ira; c/o Graymont Western Canada Inc., 200-10991 
Shellbridge Way, Richmond, British Columbia, V6X 3C6 
(25) FilingLanguage: English (CA).  
(26) Publication Language: English (74) Agent: KUMAR, Vijay et al.; Fortem IP LLP, 89 Yesler 
(30) Priority Data: Way, Suite 202, Seattle, WA 98104 (US).  
62/729,955 11 September 2018 (11.09.2018) US (81) Designated States (unless otherwise indicated, for every 
62/806,512 15 February 2019 (15.02.2019) US kind ofnational protection available): AE, AG, AL, AM, 
(71) Applicant: GRAYMONT WESTERN CANADA INC. AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, 
[CA/CA]; 200-10991 Shellbridge Way, Richmond, British CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, DO, 
Columbua, V6X 3C6 (CA). DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, 
HR, HU,lID, IL, IN, IR, IS, JO,WJ,RKE, KG,RKH, KN,RP, 
(72) Inventors: ROMANIUK, Nikolas, Andrei; c/o Graymont RR, KW, KZ, LA, LC,LK, LR, LS, LU, LY, MA, MD, ME, 
Western Canada Inc., 200-10991 Shellbridge Way, Rich- MG, MK, MN, MW,MX,MZ,NA, NG, NI, NO, NZ, 
mond, British Columbia, V6X 3C6 (CA). FOX, Jesse, 
(54) Title: IMPROVEMENT OF GEOTECHNICAL CHARACTERISTICS OF TAILINGS VIA LIME ADDITION 
100 
11 103 Mxr 17 Dw~rn 
10 Devaten 
Co0t 118 
119 
Control System 
130 
FIG. 1 
0 (57) Abstract: Methods and systems for treating tailings at an elevated pH using lime are disclosed herein. In some embodiments, the 
Sf method comprises (i) providing a tailings stream comprising bicarbonates and a pH less than 9.0, (ii) adding a coagulant comprising 
calcium hydroxide to the tailings stream to form a mixture having a pH of at least 11.5 and a soluble calcium level no more than 800 
mg/L, and (iii) dewatering the mixture to produce a product having a solids content of at least 40% by weight. In some embodiments, 
the pH and soluble calcium level of the mixture cause chemical modification of clay materials of the mixture via pozzolanic reactions.  
In some embodiments, the undrained shear strength of the product increases over a period of time of at least two days.
W O 2020/055893 A 1 ||||||11111|||||||||||||||||||||||I|I||||||||||||l|||||||||||||||||||||||||| 
OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, 
SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, 
TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW.  
(84) Designated States (unless otherwise indicated, for every 
kind of regional protection available): ARIPO (BW, GH, 
GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, TZ, 
UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, 
TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, 
EE, ES, Fl, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, 
MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, 
TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, 
KM, ML, MR, NE, SN, TD, TG).  
Published: 
- with international search report (Art. 21(3))