Waste Treatment and Utilization

in Heavy Metal Metallurgy

Jiang Kaixi

BGRIMM

Apr. 12-13, 2012, Santiago, Chile 1

M2R2

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19.17 million

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34.24 million

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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.

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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.

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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

Solid wastes’ utilization

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Copper metallurgy

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Copper Metallurgy

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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. ).

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Copper industry

11 Copper concentrates Tailing

Slag

Size: 80% -0.074mm

Size: 80% -0.038mm

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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.

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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

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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.

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Copper industry

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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%

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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.

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Copper industry

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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.

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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%.

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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%

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Zinc metallurgy

Zinc industry

Problems of the Jarosite process

Large quantity residues;

High zinc lost;

Instability and potential pollution.

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30 million tons piled

Contain 1.5 million tons

zinc (5%)

Rare metals>3000t

1 million tons

per year

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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

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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%

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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

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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.

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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.

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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.

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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

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Lead metallurgy

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Lead industry

Lead processes:

Sintering - blast furnace

ISP

Kivcet process

QSL process

SKS process

Ausmelt/ISA

Kaldo furnace

Hua Bao flash smelting (BGRIMM)

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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.

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Lead industry

Pb and Zn combined smelter is a trend for metal recovery

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Zinc plant Lead smelter

Pb-Ag residue

Zinc leaching residue

Zinc dust

Pb/Zn/Ag/Au/Slag Zn/Pb/Cu/In

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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.

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