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Waste Treatment and Utilization
in Heavy Metal Metallurgy
Jiang Kaixi
BGRIMM
Apr. 12-13, 2012, Santiago, Chile 1
M2R2
0
5
10
15
20
25
30
35
40
45
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19.17 million
tons
34.24 million
tons
46 million
tons
2006 2011 2015
Introduction
Production of top ten non-ferrous metals in China
Ranking the position 1 for 9 years in the world;
34.24 million tons in 2011;
Forecasting: 46 million tons in 2015.
2
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
About BGRIMM
Founded in 1956, ca. 3800 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
R&D
Mining Engineering
Explosives & Blasting
Engineering
Mineral Engineering
Metallurgy Engineering & Recycling
Materials
Machinery
Environmental
Engineering
Resources Evaluation
& Mineralogy
Online Instruments
& Automation
Chemical Analysis
BGRIMM’S
R&D
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;
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.
Metallurgy Department
10 10
Copper Metallurgy
10
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. ).
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.
13
Copper industry
Arsenic waste treatment:
More than 10kt arsenic goes into copper smelter every year in
China;
About 60% arsenic goes into SO2 gas;
Arsenic wastes: (1) Arsenic sulphide residue, 15-25% As
(2) Flue dust, 0.1-4% As
(3) Black copper slime, 20-25%As
14 14
BGRIMM developed
Pressure Leaching Technology
2As2S3+ 6H2O+5O2= 6S+4H3AsO4
2CuS+2H2SO4+O2= 2S + 2CuSO4 + 2H2O
Low operation cost;
High metal recovery;
Cleaning process/Environmental
friendly;
Cu\As\Bi\Re\Ag\Au\S recovery.
14
Copper industry
15 15 15
Copper industry
Pressure leaching plant for arsenic sulfide cake
This technology was adopted in Guixi Smelter to replace copper
sulfate cementation process (Sumitomo process). It was
commissioned in 2008.
• Capacity: 2000t-As2O3/a
• Recovery:
As >95% into
product,
Cu >95%,
Re >90%
16 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.
17 17
Copper industry
17
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.
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
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Copper industry
Crude selenium
To produce Se or SeO2
Copper telluride
Process: alkaline leaching --
neutralization -- electrolysis
Products: refined Te
Recovery: Te >92%
Zinc industry
Problems of the Jarosite process
Large quantity residues;
High zinc lost;
Instability and potential pollution.
22
30 million tons piled
Contain 1.5 million tons
zinc (5%)
Rare metals>3000t
1 million tons
per year
23
Zinc industry
First stage hot acid leaching solution
O2 Zinc concentrate
Pressure leaching
L/S
Residue Leaching solution
Go to lead smelter Recirculated to neutral leaching stage
BGRIMM developed
new process to avoid
producing jarosite
residue in zinc
metallurgy
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%
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%.
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 27
Zinc industry
SO2 reductive pressure leaching for recovery of Ga and Ge:
BGRIMM developed SO2 reductive leaching process to
recover Ga and Ge from zinc leaching residues:
Leaching conducted in autoclave at 105C;
Zn, Fe, Ga and Ge into leaching solution;
Pb and Ag remain in residue, Ag is enriched more than
2000g/t;
Fe3+ is less than 0.2g/L.
28 28 28
Zinc industry
SO2 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.
29 29 29
Zinc industry
SO2 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.
30 30 30 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 Fe3+ in solution
High teperature and pressure leaching to ensure zinc recovery
at second leaching stage
Precipitation Ga and Ge from first stage leaching solution
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
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
Lead industry
Pb and Zn combined smelter is a trend for metal recovery
34
Zinc plant Lead smelter
Pb-Ag residue
Zinc leaching residue
Zinc dust
Pb/Zn/Ag/Au/Slag Zn/Pb/Cu/In
35 35 35 35 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.