Waste Treatment and Utilization in Heavy Metal Metallurgy

Transcription

1 M2R2 Waste Treatment and Utilization in Heavy Metal Metallurgy Jiang Kaixi BGRIMM Apr , 2012, Santiago, Chile 1

2 Introduction Production of top ten non-ferrous metals in China Ranking the position 1 for 9 years in the world; million tons in 2011; Forecasting: 46 million tons in million tons million tons 46 million tons

3 Introduction 800 mil t waste water discharged into environment in 2011; 220 kt dust in off-gas emission annually. 310 mil t solid waste annually. 3

4 About BGRIMM Founded in 1956, ca employees, but only 1000 professionals; A state-owned enterprise administrated by SASAC the State Asset Supervision and Administration Commission. A main Chinese technology supplier of innovative technologies, technical and engineering service in mining and metallurgy for nonferrous metals. Research & Development Consulting & Engineering Manufacturing

5 BGRIMM S R&D Chemical Analysis Mining Engineering Explosives & Blasting Engineering Online Instruments & Automation Resources Evaluation & Mineralogy R&D Mineral Engineering Metallurgy Engineering & Recycling Environmental Engineering Machinery Materials

6 Metallurgy Department Pyro- and hydrometallurgy Copper bath smelting (a side-blown) technology; Lead flash smelting; Fluidized-bed roasting for zinc, cobalt pyrite and arsenic containing gold concentrates, etc. Direct reduction iron; Process R&D for nickel laterite; Leaching (pressure, heap, tank leaching); SX and ion exchange; EW and electrolysis; Slurry electrolysis;

7 Metallurgy Department Valuable metals comprehensive recovery like rare metal extraction of metallurgical flow-sheets; Waste treatment and utilization; Oceanic mineral resource metallurgy; Secondary metal resource recycling; Recycling of PGMs in BGRIMM-Xuzhou Institute of Metal Recycling.

8 Solid wastes utilization 8

9 Copper metallurgy 9

10 Copper Metallurgy Slag treatment: Dressing is the trend -- Flotation: also for smelting slags from Flash furnace and local smelting processes -- High copper recovery; -- Low energy consumption; -- Cost: about 2-2.5kg Cu per 1t slag; -- Magnetite from converting slags (50-55% Fe in iron conc. ). 10

11 Copper industry Slag Size: 80% mm Size: 80% mm Copper concentrates Tailing 11

12 Copper industry Practice in Guixi Smelter of Jiang Copper: Copper slag: Cu 1.82%, Fe 40.98%, Pb 0.85%, Zn 2.64%; Copper grade in concentrate: 29.93%; Copper recovery: 87.48%; Copper in tailings: 0.24%; Operation cost: 100 RMB/t slag, total cost ca. 2kg copper. 12

13 Copper industry Arsenic waste treatment: More than 10kt arsenic goes into copper smelter every year in China; About 60% arsenic goes into SO 2 gas; Arsenic wastes: (1) Arsenic sulphide residue, 15-25% As (2) Flue dust, 0.1-4% As (3) Black copper slime, 20-25%As 13

14 Copper industry BGRIMM developed Pressure Leaching Technology 2As 2 S 3 + 6H 2 O+5O 2 = 6S+4H 3 AsO 4 2CuS+2H 2 SO 4 +O 2 = 2S + 2CuSO 4 + 2H 2 O Low operation cost; High metal recovery; Cleaning process/environmental friendly; Cu\As\Bi\Re\Ag\Au\S recovery. 14

15 Copper industry This technology was adopted in Guixi Smelter to replace copper sulfate cementation process (Sumitomo process). It was commissioned in Capacity: 2000t-As 2 O 3 /a Recovery: As >95% into product, Cu >95%, Re >90% Pressure leaching plant for arsenic sulfide cake 15

16 Copper industry BGRIMM also developed the process to treat arsenic sulphide cake and black copper mud for Tongling Copper Smelter. It is becoming a standard process for copper smelters. 16

17 Copper industry Recovery of rare and precious metals from flue dusts and anode slimes -- Mo, Re, Ge, In from dusts; -- Se and Te from anode slimes; -- Au, Ag and PGMs from anode slimes; -- Sb, Bi from both. 17

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19 Copper industry Pressure leaching In XiangGuang Copper, the anode slime treatment capacity is 2400t/a. Guixi and Tong Ling Kaldo process was put into production in 2009, with anode slime treatment capacity 4000t/a. The recovery of Au and Ag is over 99%. 19

20 Copper industry Crude selenium To produce Se or SeO 2 Copper telluride Process: alkaline leaching -- neutralization -- electrolysis Products: refined Te Recovery: Te >92% 20

21 Zinc metallurgy 21

22 Zinc industry Problems of the Jarosite process Large quantity residues; High zinc lost; 1 million tons per year 30 million tons piled Contain 1.5 million tons zinc (5%) Rare metals>3000t Instability and potential pollution. 22

23 Zinc industry BGRIMM developed new process to avoid producing jarosite residue in zinc metallurgy O 2 First stage hot acid leaching solution Zinc concentrate Pressure leaching L/S Residue Leaching solution Go to lead smelter Recirculated to neutral leaching stage 23

24 Zinc industry Jarosite process Pressure leaching process Output 100kt 130kt Zinc recovery 90-92% 95% Operation cost 4300RMB/tZn 4150RMB/tZn Iron residue 70-80kt/a 30-35kt/a Zinc in residue 6% 2-3% 24

25 Zinc industry Recovery of rare and precious metals: Rotary kiln volatilization process in Zhuzhou and Laibin, etc. Ge, In, Zn goes to dust; Ga remains in slag; Ge recovery less than 55%; Ga recovery less than 10%; Ag recovery less than 20%. 25

26 Zinc industry Indium recovery BGRIMM developed a indium recovery process with iron removal as hematite Laibin Zinc Plant. Recovery: Zn 96%, In 87%. Pilot test finished 26

27 Zinc industry SO 2 reductive pressure leaching for recovery of Ga and Ge: BGRIMM developed SO 2 reductive leaching process to recover Ga and Ge from zinc leaching residues: Leaching conducted in autoclave at 105 C; Zn, Fe, Ga and Ge into leaching solution; Pb and Ag remain in residue, Ag is enriched more than 2000g/t; Fe 3+ is less than 0.2g/L. 27

28 Zinc industry SO 2 reductive leaching for recovery of Ga and Ge: Ga and Ge precipitated by limestone; SX for separation of Ga and Ge; G315 was used as extractant produced by BGRIMM. 28

29 Zinc industry SO 2 reductive leaching for recovery of Ga and Ge: Recovery: Zn 90%, Ga 85%, Ge 78%, Pb 98%, Ag 99%; Pb-Ag residue can be enriched more than 10 times; Lab and pilot tests were finished by BGRIMM and Fankou Lead and Zinc Mine. 29

30 Zinc industry Two stages pressure leaching for Ga and Ge recovery: Low temperature and pressure leaching with weak oxiation at First stage to reduce Fe 3+ in solution High teperature and pressure leaching to ensure zinc recovery at second leaching stage Precipitation Ga and Ge from first stage leaching solution 30

31 Lead metallurgy 31

32 Lead industry Lead processes: Sintering - blast furnace ISP Kivcet process QSL process SKS process Ausmelt/ISA Kaldo furnace Hua Bao flash smelting (BGRIMM) 32

33 Lead industry Hua Bao flash smelting technology: Developed by BGRIMM Low capital and operation cost Low energy consumption Wide flexibility of raw materials High metal recovery for Pb, Zn, Ag, etc. 33

34 Lead industry Pb and Zn combined smelter is a trend for metal recovery Pb-Ag residue Zinc leaching residue Lead smelter Zinc plant Pb/Zn/Ag/Au/Slag Zinc dust Zn/Pb/Cu/In 34

35 Conclusions Solid wastes treatment will become a focus after the problems of gas, dusts and waste water are solved; Joint technology by mineral process and metallurgy is the trend for metal recovery from wastes; Copper, lead and zinc complex smelter may be the trend for interchange materials or wastes to recovery metals and reduce slag and residues quantity; Hazardous waste (arsenic, cadium residues, etc) should be treated by advanced and clean process like pressure leaching; Jarosite process should be replaced by pressure leaching; Spent lead battery should be treated combined with lead concentrate by advanced flash smelting process. 35

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