Andrzej Luszczkiewicz, Tomasz Chmielewski · Andrzej Luszczkiewicz, Tomasz Chmielewski Wroclaw University of Technology, Wroclaw, Poland Andrzej Konieczny KGHM „Polish Copper”,

Andrzej Luszczkiewicz, Tomasz Chmielewski Wroclaw University of Technology, Wroclaw, Poland

Andrzej Konieczny KGHM „Polish Copper”, Lubin, Poland

Luszczkiewicz A., Chmielewski T., Konieczny A., Leaching and Flotation of Concentrate and Middlings ….

Main copper producers

KGHM (Poland)

Aitik (Bolinden) Highland Valley

(Teck/Cominco/Billiton)

Bingham (Rio)

Morenci (Phelps D)

Caridad (Grupo M.)

Kidd Ck. (Falconbridge)

Palabora (Rio/Anglo)

Nchanga (ZCCM/Anglo)

Norilsk

Erdenet

Dexing Sharcheshmeh

Batu Hijau (Newmont)

Grasberg (Rio/F’port)

OK Tedi (BHP)

Mt Isa (MIM)

Olympic Dam (WMC)

Chuquicamata (Codelco)

Escondida (BHP/Rio)

Los Pelambres (Antofagasta)

El Teniente (Codelco)

Neves Corvo (ex Rio)

Collahuasi (Anglo/F’bridge)

Cu mine production (2011) – 16.0 mln t KGHM „Polish Copper” (2011) – 571 kT


KGHM deposit’s location


KGHM Lubin-Glogow Mining Area Deposit

UK

F

D

I

PL KGHM


Generalized

lithostratigraphic

section

of the basal Zechstein

and the position of the

Kupferschiefer ore

series

Geology of the Lubin- -Glogow Basin


Typical Cu-Ag section containing grey sandstone (A), boundary dolomite

(B), dolomitic shale (C), black shale (D) and dolomite (E).

Cross section of sandstone - shale - dolomite

Dolomite ore

Shale ore

Sandstone ore


Current limiting conditions in Polish copper industry

Luszczkiewicz A., Chmielewski T., Konieczny A., Leaching and Flotation of Concentrate and Middlings …. Luszczkiewicz A., Chmielewski T., Konieczny A., Leaching and Flotation of Concentrate and Middlings ….

Difficulties in the flotation processes caused by the presence of the black shale in the processing plant


How to elevate both the metals recovery

and the concentrate grade?

enhance mechanical comminution as a method of liberation

intensify froth flotation as a method of beneficiation

limit of features has been reached

Current flotation parameters



New approach required

superior chemical alteration of the ore,

by-product or concentrate by means

of inexpensive and environmentally safe medium – sulphuric acid


FEED

(middlings from cleaning flotation)

LEACHING WITH

H2SO4 (~70%)

CLEANING

FLOTATION

H2SO4

from smelter

Final concentrate

Final

tailings

General concept of hybrid FLF process of ore beneficiation


Leaching of carbonate intergrowths in H2SO4

Leaching time


Principle:

Chemical reaction of H2SO4 with carbonates of calcium

(CaCO3) and magnesium (MgCO3) - major components of

intergrowth with metals bearing minerals:

CaCO3 + H2SO4 + H2O = CaSO4·2H2O + CO2

MgCO3 + H2SO4 = MgSO4 + CO2

Chemistry of acidic carbonate leaching

Decomposition of acid-consuming components

Liberation of disseminated sulphide particles


Beneficial role of CO2 in non-oxidative leaching

CO2 creates the non-oxidative atmosphere in

the leaching slurry and prevents the

digestion of sulphide minerals.

The redox potential is to low to leach out

copper and other metals in sulphidic form


Flowsheet of laboratory procedure (both unleached and leached with H2SO4)

Sample of commercial product from the plant

Slurry mixing and batch test samples preparation

Determination of maximum H2SO4 consumption for

carbonates decomposition

Leaching with H2SO4 with 70% carbonate decomposition

Flotation for gypsum removing

Fractional flotation tailings

midlings C-3 C-2 C-1

Refe

rence e

xperim

ents


Flowsheet of pilot plant tests of chemical modification and subsequent flotation of the feed in a continuous system

with indicated points of sampling

Repulpator

H2SO4

Reactor 3

Reactor 1

Reactor 2

Concentrate

Feed to flotation after leaching

K

De-gypsing flotation

Scavenger flot.Cleaning flotation

Tailing

Feed to leachingFeed to comparative

experiment(without leaching)

Feed (middlings - by-product from 1st cleaning operation)


FEED (middlings from cleaning flotation)

tailings

CaSO4·2H2O, MgSO4

CO2 To the atmosphere

LEACHING

concentrate

ΔβCu= +3.5%, ΔεCu= +4.0%

ΔβAg= +250 g/t, ΔεAg= +3.5%

H2SO4, from smelter

CLEANING

FLOTATION

Pilot plant tests - setup


Commercial application

Final tailingsFinal

concentrate

regrindHC

C M

M

C

2nd cleaning

Middlings cleaning

1st cleaning

Rougher-scavenger

Rougher flotation

BM

C

Feed from grinding

circuit 85% - 45mm

M

HC

T

Flowsheet of the Polkowice Concentrator

Hard-to-tread middlings

was selected to leaching

and flotation operation


Final tailingsFinal

concentrate

regrindHC

C M

M

C

2nd cleaning

Middlings cleaning

1st cleaning

Rougher-scavenger

Rougher flotation

BM

C

Feed from grinding

circuit 85% - 45mm

M

HC

T

Analysis of industrial process at the Polkowice Concentrator. Flowsheet of the 1st and 2nd technological line

C - concentrate BM - ball mill

M - middlings HC - hydrocyclone

T - tailing

Final

concentrate

1st cleaning

Rougher-scavenger

C

BM

C

M

C1

T

C

HC

Feed from grinding

circuit 85% - 45mm

Scavenger de-gypsing

Rougher flotation

Leaching

2nd cleaning

C3

T

regrind


Final tailings

M2C2

T1

M1

flotation-leaching-flotation (FLF) node




T - tailing sampling points

Final

concentrate

1st cleaning

Rougher-scavenger

C

BM

C

M

C1

T

C

HC

Feed from grinding

circuit 85% - 45mm


Rougher flotation

Leaching

2nd cleaning

C3

T

regrind


Final tailings

M2C2

T1

M1

Analysis of industrial process at the Polkowice Concentrator. Flowsheet of the 1st technological line with chemical treatment of middlings (by-product

from I cleaning) with sampling points indicated

Product samples selected from

technological FLF node

C-1 Tailing

Fractional flotation

C-2 C-3 C- n .

Fractions of concentrate

. . .

Feed to leaching




T - tailing sampling points

Final

concentrate

1st cleaning

Rougher-scavenger

C

BM

C

M

C1

T

C

HC

Feed from grinding

circuit 85% - 45mm


Rougher flotation

Leaching

2nd cleaning

C3

T

regrind


Final tailings

M2C2

T1

M1

Product samples selected from

technological FLF node

C-1 Tailing

Fractional flotation

C-2 C-3 C- n .

Fractions of concentrate

. . .

Analysis of industrial process at the Polkowice Concentrator. Flowsheet of the 1st technological line with chemical treatment of middlings (by-product

from I cleaning) with sampling points indicated

Leached products



Grade-recovery curves of flotation analysis of industrial products samples selected

from flotation-leaching-flotation (FLF) node

0

5

10

15

20

25

30

35

0 20 40 60 80 100

Co

pp

er

co

nte

nt

in

co

nce

ntr

ate

, %

Copper recovery, %

Flot. feed to leaching Rw=26%


Flot. leached products Rw=26%


Rw – degree of

carbonates

decomposition


Fuerstenau recovery-recovery curves of flotation analysis of industrial products samples selected from FLF node

0

20

40

60

80

100

0 20 40 60 80 100

Reco

very

of

barr

en

part

of

ore

in

ta

ilin

g, %

Copper recovery in concentrate, %

Lack of upgrading






Final tailingsFinal

concentrate

regrindHC

C M

M

C

2nd cleaning

Middlings cleaning

1st cleaning

Rougher-scavenger

Rougher flotation

BM

C

Feed from grinding

circuit 85% - 45mm

M

HC

T

Comparison of industrial process on 1st and 2nd technological line at the Polkowice Concentrator



T - tailing

Final

concentrate

1st cleaning

Rougher-scavenger

C

BM

C

M

C1

T

C

HC

Feed from grinding

circuit 85% - 45mm


Rougher flotation

Leaching

2nd cleaning

C3

T

regrind


Final tailings

M2C2

T1

M1


Comparison of industrial process on 1st and 2nd technological line at the Polkowice Concentrator

84

85

86

87

88

89

90

91

92

93

94

95

4 5 6 7 8 9

Co

pp

er

reco

very

, %

Weight percent

Line 2 (standard process)

Line 1 (process with middlings leaching)

concentrate

ΔβCu=+0.6%, ΔεCu=+3.4%

ΔβAg=+150 g/t, ΔεAg=+2.9%


The application of non-oxidative leaching

of carbonates from copper concentrate

and middlings with sulfuric acid

in the flotation circuit system enables

a significant increase of recovery and

concentrate grade to the level which can

not be achieved by introduction

of new grinding and flotation equipment

or by modification

of existing flotation circuits.

SUMMARY

Luszczkiewicz A., Chmielewski T., Konieczny A., Leaching and Flotation of Concentrate and Middlings …. Luszczkiewicz A., Chmielewski T., Konieczny A., Leaching and Flotation of Concentrate and Middlings ….

Remarkable increase in flotation recovery and concentrate grade was observed for Cu and Ag,

No need to change the existing flotation circuits,

Effective utilization of H2SO4,

No hazardous effect of leaching products.

SUMMARY


A new hybrid FLF process involving sulphuric acid treatment

of flotation middlings combined with a subsequent flotation in

the commercial scale resulted in a significant increase of

process selectivity.

Originally designed methodology, referred as flotation

analysis, was elaborated for evaluation of sampled material

in laboratory experiments.

A beneficial effect of the chemical pre-treatment of the

flotation middlings on flotation selectivity was shown by

means of floatability curves for unleached and leached

feeds.

It was found that the application of the FLF process on the

industrial scale resulted in an increase of copper recovery by

3.4%.

CONCLUSIONS


Andrzej Luszczkiewicz, Tomasz Chmielewski · Andrzej Luszczkiewicz, Tomasz Chmielewski Wroclaw University of Technology, Wroclaw, Poland Andrzej Konieczny KGHM „Polish Copper”,

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