Method for pretreating refractory gold ore by employing microwave calcining

A microwave roasting and pretreatment technology, applied in the direction of improving process efficiency, can solve the problems of unsuitable ore, long process flow, low slurry concentration, etc., and achieve the effect of shortening the processing time

Inactive Publication Date: 2008-07-23
SHENYANG LIGONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantages are: ①The roasting process produces a large amount of SO 2 and As 2 o 3 ② Strict process requirements; ③ Influenced and restricted by the sulfuric acid market; ④ The process is long and complicated; In high-grade gold concentrates, after the roasting temperature exceeds 700°C, arsenic and gold form a low-melting arsenic-gold alloy and volatilize, resulting in gold loss
The disadvantages are: ① due to high temperature and pressure, high requirements on equipment and materials, and potential safety hazards; ② high maintenance costs; ③ strict control conditions, otherwise the sulfur produced by the reaction will wrap gold again, affecting the recovery of gold; ④ high production costs; ⑤ Not suitable for ores containing gold and charcoal; ⑥ Cannot be recycled for arsenic and sulfur minerals
Disadvantages: ①Arsenic removal initiator needs to be added; ②Proprietary equipment must be used; ③It is not suitable for ores containing gold charcoal; ④Associated minerals such as arsenic and sulfur cannot be recycled
The disadvantages are: ①The pulp concentration is low, and the pretreatment time is long; ②It is not suitable for processing ores with high arsenic content; ③The requirements for the aerator of the bioreactor are strict; ④The tail liquid generated needs to be neutralized; ⑤Investment Higher, high production cost; ⑥need suitable strains for ore; ⑦not suitable for ore containing robbing gold charcoal

Method used

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  • Method for pretreating refractory gold ore by employing microwave calcining

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] A gold mineral is a flotation gold concentrate containing arsenic, sulfur and carbon. The gold concentrate contains minerals such as pyrite, marcasite, arsenopyrite, graphite and organic carbon that affect gold leaching, and the embedded gold particle size is fine. The multi-element analysis of minerals is shown in Table 1.

[0029] the element

Au(g / t)

Ag(g / t)

As

Fe

S

C

Sb

Content (%)

the element

Content (%)

39.63

Cu

0.02

23.84

Pb

0.03

0.70

Zn

0.05

15.55

CaO

6.02

15.11

MgO

3.25

3.97

SiO 2

39.17

1.49

Al 2 o 3

7.02

[0030] The occurrence state analysis of gold minerals is shown in Table 2.

[0031]

Occurrence status

Monomer

bare gold

Sulfide

Package gold

carbonate

Package gold

quartz

Package gold

total

...

Embodiment 2

[0035] A gold concentrate is composed of gold-arsenic concentrate and pyrite-containing concentrate. The chemical composition is shown in Table 3.

[0036] the element

[0037] Microwave roasting test conditions: raw ore 100g, roasting temperature 485°C, roasting time 12min, power 5kw. The contents of S and As in the calcined sand after microwave roasting were 2.23% and 0.52%, respectively. The calcined sand is finely ground and then cyanide leached. The gold leaching rate is 96.69%. The recovery rate of sulfur is 92%, and the sulfur dioxide content in the flue gas is 850mg / m 3 . After conventional roasting, the gold leaching rate is 59.03%.

Embodiment 3

[0039] A gold mine is a refractory metallurgical mine containing arsenic, sulfur and carbon. The gold ore contains pyrite, orthorhombite, arsenopyrite, graphite and amorphous carbon and other minerals that affect gold leaching, and the gold embedded particle size is fine, containing 23% wrapped gold. The main chemical composition of I flotation gold concentrate is shown in Table 4.

[0040] the element

[0041] Microwave roasting test conditions: 100g of the above-mentioned refractory metallurgical ore was roasted in a nitrogen atmosphere, the roasting temperature was 500°C, the roasting time was 10min, and the power was 4kw. The calcined sand is finely ground first, and then cyanide leaching is carried out. After microwave roasting pretreatment, the gold leaching rate was 97.89%. The recovery rate of sulfur is 94.5%, and the content of sulfur dioxide in the flue gas is 860mg / m 3 . After conventional roasting, the gold leaching rate is 62.33%.

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Abstract

The invention relates to a method to pre-treat a hard-to-leach gold ores-pyrite by microwave roasting, which is characterized in that the gold ores-pyrite or fine gold ores-pyrite with the granularity being 200 meshes which takes 90% to 95% of the whole gold ores-pyrite is positioned in a reaction chamber of a microwave roasting oven, a nitrogen is filled fully into the reaction chamber, starting the microwave roasting oven, the gold ores-pyrite or fine gold ores-pyrite is radiated and roasted by the microwave in the nitrogen atmosphere, the roasting temperature is 450 to 580 degree centigrade, the power is 4 to 6kw, the microwave roasting oven stops working after roasting for 5 to 20 minutes, a roasted product is made when the roasting gold ore-pyrite is taken out. The method to pre-treat a hard-to-leach gold ores-pyrite by microwave roasting has the advantages of increasing the gold leaching yield of the hard-to-leach gold ores-pyrite up to over 90%, reaching purpose of the environment protection because the sulfur is precipitated as a free sulfur without the recovery process of smoke and dust, and saving the energy because the microwave roasting process is adopted and the pretreatment time is greatly shortened.

Description

technical field [0001] The invention relates to a treatment method of microwave heating gold ore and gold concentrate, which is used for the pretreatment of gold ore and gold concentrate containing high arsenic and high sulfur, and is also used for the pretreatment of carbon-containing ore; microwave roasting pretreatment Methods of gold ore and gold concentrate, protection of inert gas, recovery of elements such as arsenic and sulfur, and other metallurgical and mineral technology fields. Background technique [0002] At present, the refractory gold ore resources are almost all over the gold-producing countries in the world. There are relatively large reserves in the United States, Canada, Australia, Russia, Brazil, South Africa and other countries. In my country, about 1,000 tons of gold reserves have been identified or basically identified in high-arsenic and high-sulfur gold ores, mainly scattered in Yunnan, Guizhou, Guangxi, Sichuan, Shaanxi, Gansu, Anhui, Liaoning, Qi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B1/02C22B11/02
CPCY02P10/20
Inventor 魏莉
Owner SHENYANG LIGONG UNIV
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