Technological innovation in Córrego do Sítio Mineração - A study of technical and economic aspects by using sensor-based sorting for refractory gold ore

Vinicius Moreira Assis ⁴E-mails: 4 vmassis@anglogoldashanti.com.br

AngloGold Ashanti Ltd, Córrego do Sítio Mineração, Metalurgia, Departamento de Metalurgia, Santa Bárbara - Minas Gerais - Brasil.

Andréia Bicalho Henriques ⁵ 5 abicalho@demin.ufmg.br

Universidade Federal de Minas Gerais - UFMG, Escola de Engenharia, Departamento de Engenharia de Minas, Belo Horizonte - Minas Gerais - Brasil.

Mariana Gazire Lemos ⁶ 6 mglemos@anglogoldashanti.com.br

AngloGold Ashanti Ltd, Córrego do Sítio Mineração, Metalurgia, Departamento de Serviços Técnicos, Nova Lima - Minas Gerais - Brasil.

Jose Augusto Dumont ⁷ 7 jadumont@anglogoldashanti.com.br

AngloGold Ashanti Ltd, Córrego do Sítio Mineração, Metalurgia, Departamento de Serviços Técnicos, Nova Lima - Minas Gerais - Brasil.

	Average thickness m	Strike m	Mass t	Grade g/t	Dilution plan %
Stage 1	1.73	34	1,040	3.35	42
Stage 2	2.64	15	936	2.10	63
Stage 3	2.30	21	1,722	1.99	65

	Mass t	Au g/t
Mine planned	3,698	2.40
Ore mined	3,935	3.02
Ore sorting recalculated grade	4,246	2.51

	Mass t	Au g/t	S %
Undersize ore (-10 mm)	1,231	3.08	0.41
Oversize ore (+10 mm - 45 mm)	3,015	2.28	0.36

		Mass g	Au g/t	S %	C %	Mass pull %	Gold recovery %
Run 1	Feed	1000	2.33	0.55	1.80
	Concentrate	55	24.70	2.82	2.32	5.52	58.46
	Tailings	945	1.03	0.42	1.77
	Feed	1000	2.48	0.59	1.80
Run 2	Concentrate	51	30.36	3.70	2.34	5.09	62.24
	Tailings	949	0.99	0.43	1.77
	Feed	1000	2.43	0.61	1.81
Run 3	Concentrate	48	30.82	3.66	2.41	4.81	61.09
	Tailings	952	0.99	0.46	1.78
	Feed	1000	2.41	0.58	1.80
Average	Concentrate	51	28.63	3.39	2.36	5.14	60.60
Average	Tailings	949	1.00	0.43	1.77

		Mass g	Au g/t	S %	C %	Sb %	Fe %	As %
Run 1	Feed	945	1.03	0.42	1.77	0.02	7.06	0.23
	Concentrate	132	6.46	2.38	1.83	0.06	11.16	1.10
	Tailings	812	0.14	0.10	1.76	0.01	6.39	0.09
	Feed	945	0.99	0.43	1.77	0.02	7.50	0.27
Run 2	Concentrate	132	6.33	2.49	1.83	0.07	11.73	1.29
	Tailings	813	0.12	0.09	1.76	0.01	6.81	0.10
	Feed	952	0.99	0.46	1.78	0.01	6.79	0.24
Run 3	Concentrate	134	5.93	2.44	1.86	0.05	9.72	0.88
	Tailings	817	0.18	0.13	1.77	0.01	6.31	0.14
	Feed	947	1.00	0.43	1.80	0.02	7.12	0.25
Average	Concentrate	133	6.24	2.44	2.36	0.06	10.87	1.09
Average	Tailings	814	0.15	0.11	1.77	0.01	6.50	0.11

	Mass %	Au %	S %	C %	Sb %	Fe %	As %
Run 1	14.00	88.26	79.49	14.48	54.98	22.14	66.56
Run 2	13.98	89.55	81.80	14.45	55.83	21.87	67.70
Run 3	14.13	84.42	75.54	14.74	50.70	20.22	50.84
Average	14.04	87.41	78.94	14.56	53.84	21.41	61.70

Input	Units	Value	Condition
Fines (10 mm) by passing sorter	per cent of total feed	29.0	tested
Sorter crushing & pre-screen upper size	mm	45	tested
Sorter crushing & pre-screen lower size	mm	10	tested
XRT sorter waste reject	%	68.3	tested
XRT sorter concentrate	%	31.7	tested
LASER sorter waste reject	%	72.7	tested
LASER sorter concentrate	%	27.3	tested
XRT+LASER sorter waste reject	%	35.3	tested
XRT+LASER sorter concentrate	%	64.7	tested
XRT+LASER overall recovery (including fines)	%	91.5	tested
Average processing plant recovery	%	89.9	tested

Input	Units	Value	Condition
Underground variable costs	US$/t	29.0	assumption
Ore Sorting cost	US$/t	5.0	assumption
Sorter concentrate/rejects load & haul	US$/t	1.2	assumption
Mill plant variable cost	US$/t	30.3	assumption
Federal taxation	%	1.50	assumption