Sulfide ore acid leaching - Concord process

Posted on

    The main copper mineral ore was Konkola chalcocite, bornite, chalcopyrite followed. Therefore, its concentrate is characterized by high copper, low sulfur, low iron and high silicon, and contains cobalt minerals, so it must be equipped with pyrite and lime during smelting. However, these features make it ideal for pressure leaching. Konkola deep ore accounts for 22% of the copper minerals bornite, chalcocite 18%, 11% chalcopyrite, covellite 5%, mainly gangue potassium feldspar (19%), quartz ( 8% ) and mica . Cobalt mainly coexists with copper minerals.
South Africa's Anglo-american Ami Laboratory (AAC) was commissioned to smelting Konkola mine, combined with the use of hard Nchanga rule of mine, we put forward a joint wet process acid to maintain a balance between supply and demand of [1], The flow chart is shown in the figure below.

AAC 's experiments took a total of six different Chinkel refractory samples, one of which was listed in the table below along with the Concord concentrate samples. After a sufficient small experiment, a continuous intermediate factory experiment was carried out according to the above flow chart, and the scale was 4kg /h concentrate and 2kg /h difficult to mine. The oxidant is pure oxygen. The two-stage atmospheric leaching conditions for sulfide ore leaching and difficult smelting are shown in the following table .

Typical composition of Concora concentrate and Chinko Laiye

Ingredient %

Cu

Co

Fe

Al

Mg

Ca

Mn

Ni

Si

Zn

CO 3

S

Concora concentrate

41.44

0.4

6.51

3.01

0.88

0.35

0.02

<0.01

10.22

<0.01

2

About 15

Difficult to mine

1.03

0.06

0.94

5.26

3.48

0.58

0.14

<0.01

29.7

0.02

2.48

　

Concord process pilot leaching conditions

mineral

Process

Temperature / °C

Residence time / h

Total pressure / kPa

Oxygen partial pressure / kPa

Sulfide ore

Decomposition of carbonate

65

3

2300

700

　

Pressure leaching

200

1

Difficult to mine

a constant pressure

30

2

　

Two-stage atmospheric pressure

65

6

[next]

The figure below shows the average concentration distribution of copper, iron, diamond and free acid at each sampling point when the leaching process reaches steady state. Sampling points 1 and 2 are the components before and after the decomposition of carbonate. When acid is added, both copper and iron are obviously dissolved, and the free acid rises to 49g /L. Sample points 3 to 8 are samples of 6 chambers of the autoclave, respectively, since the sample is from 200 °C In the kettle, a large amount of steam is volatilized during sampling, and the concentration of the solution in the kettle is about the value in the figure multiplied by 0.8 . 9 is a sample taken from a decompression tank.

    These results indicate that the iron leached in the kettle is quickly oxidized, hydrolyzed, and then precipitated. The precipitate includes basic sulfates of hematite and iron. The acid is mainly consumed in the leaching reaction of copper and cobalt. The analysis of the solid sample shows that the copper has been leached at about 40 mim , and the cobalt leaching takes 60 minutes to complete. The order of leaching of copper minerals is: porphyrite > chalcopyrite > copper blue > chalcopyrite.

Torque-slotted screw

Torque-Slotted Screw,Star Shaped Screw,Star Head Screw,Star Drive Screws

Suzhou Chenran Precision Fasteners Co., Ltd. , https://www.chenranhardware.com