About Us

Henan LIMING Heavy Industry Science and Technology Co. LTD which mainly manufacture large and medium-sized crushing and grinding equipments was founded in 1987. It is a modern joint-stock corporation with research, manufacturing and sales together. The Headquarter is located in HI-TECH Industry Development Zone of Zhengzhou and covers 80000 m ². Another workshop in Shangjie Industry Park covers 67000 m ². Over the more than 30 years, our company adheres to modern scientific management system, precision manufacturing, pioneering and innovation. Now LIMING has become the leader in domestic and oversea machinery manufacturing industry.

120

million

cubic meters

Industrial chain production base

70

national patents

689sets

national patents

170

Equipment service country

Company Culture

core values of the company

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Standardization, value, serialization, and differentiation will always exceed our contract

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Case Scene

Ammoniacal thiosulphate leaching of gold ore

attempt is made to assess the feasibility of ammoniacal thiosulphate leaching of gold ore samples from two different mines namely Akeshi and Hishikari of Japan. In this study, the effect of thiosulphate concentration, effect of ammonia, effect of cupric ions, and few other variables affecting the gold leaching have been studied. The ammoniacal thiosulphate leaching of gold is dependant on both ammonia and thiosulphate

Thiosulphate Leaching SGS

Thiosulfate leaching of gold ores has great potential to reduce the impact on the environment. Unlike cyanide, which is highly toxic, the chemicals used in the thiosulfate leaching process are benign. This technology offers great potential in those jurisdictions where the use of cyanide is banned outright, or is subject to intense negative publicity for environmental reasons

Ammoniacal thiosulfate leaching of refractory oxide gold ore

10/07/2017  Ammoniacal thiosulfate leaching of refractory oxide gold ore was investigated. According to X-ray fluorescence and fire assay analyses, the ore contained about 33.01 wt% Si, 8.53 wt% Al, 7.26 wt% K, 3.00 wt% Fe, and 2.80 ppm Au. Moreover, X-ray diffraction analysis and mineralogical studies using polished thin sections showed that the ore was composed of quartz, epidote, muscovite, and

Sodium Thiosulphate Gold Leaching - 911 Metallurgist

02/06/2016  Sodium Thiosulphate Gold Leaching. The gold industry has been seeking alternative reagents for leaching gold from low-grade ores for the past 25 years. The cost and transport of cyanide, the poor recovery of gold from carbonaceous ores, the lack of selectivity of cyanide towards copper minerals and the cost of waste treatment are real factors which ...

THIOSULPHATE LEACHING – AN ALTERNATIVE TO CYANIDATION

THIOSULPHATE LEACHING – AN ALTERNATIVE TO CYANIDATION IN GOLD PROCESSING ALTERNATIVES TO CYANIDE IN GOLD PROCESSING THIOSULPHATE LEACHING Thiosulphate leaching is a process that removes gold from gold bearing ores without the use of cyanide. Although not as aggressive a leaching agent as cyanide, thiosulphate offers several technological

A study of thiosulfate leaching of gold from carbonaceous ...

It was also shown that thiosulfate will leach gold from oxide ores but not as effectively as cyanide. While a high percent extraction of gold was obtained from the carbonaceous ore, poor recovery of gold was observed from the sulfide ore, which is also a refractory ore as is the carbonaceous ore. A comparison of thiosulfate with cyanide leaching of gold from carbonaceous ore showed that thiosulfate

Effect of additives on thiosulfate leaching of a gold ore

ore. Thiosulfate and gold thiosulfate species interact with the mineral particles (especially sulfide minerals) as well as carbonaceous matter, causing instability of the gold thiosulfate species. Addition of EDTA increased gold recovery but reduced the initial kinetics. This effect became more noticeable with increased EDTA concentration up to

thiosulfate leaching - Gold Refining Forum

19/05/2011  Has anyone here actually used thiosulfate for leaching gold ore,and had positive results,that can be repeatable as a real leaching process? Has anyone found a real working precipitation process to recover the gold,that works well,and is dependable? Also getting the gold out of the precipitates seems to be a real pain. Any real answers for this,would be appreciated.

Thiosulfate Leaching Process for Gold Extraction

Experimental and modelling work for gold thiosulfate leaching system have been conducted in this study. The adsorption of thiosulfate, polythionates, gold thiosulfate and copper complexes onto strong based anion exchange resin of Purolite A500/2788 in single and multiple components resin-solution systems, has been investigated. The experimental procedures and speciation methods for the

Gold recovery from refractory gold concentrates by ...

Mohammadi et al. investigated ammoniacal thiosulfate leaching of refractory oxide gold ore, and they obtained maximum gold extraction of 55% (Mohammadi et al., 2017). Shen et al. had researched the direct thiosulfate leaching of gold from refractory ore, and they achieved gold recovery of only 70% (Shen et al., 2013). Li et al. studied the best conditions of roasting and oxidizing refractory ...

A study of thiosulfate leaching of gold from

The objective of this study was to investigate leaching of gold from carbonaceous ore using ammoniacal thiosulfate solutions, and to determine the consumption of thiosulfate during leaching. The quantitative determination of thiosulfate in the leached solution in the presence of sulfite and sulfate ions was accomplished by means of flow injection analysis with electrochemical detection. Lower ...

Effect of additives on thiosulfate leaching of a gold ore

the effect of selected additives on thiosulfate leaching of a gold ore, i.e. EDTA, carboxy methyl odium dodecyl sulfate (SDS) was investigated. EXPERIMENTAL Materials A milled gold ore sample with a solid content of 50% was provided by a gold mine and used in the leaching tests without further treatment. The gold ore sample was a refractory ore mainly containing 6 g Au/t, about 3% pyrite and 0 ...

GOLD LECHING FROM A SAUDI ORE BY THE NONPOLLUTING ...

Gold leaching from a Saudi ore by the nonpolluting thiosulfate process 61 thiosulfate media other than copper and ammonia (Zhang et al., 2005; Chandra et al., 2005). Carbonaceous sulfide ores after oxidative pre-treatment are typically very easy to leach with thiosulfate, while complex metal sulfide ores are much more difficult to treat. The presence of various amount of pyrite, pyrrhotite ...

Improvement of thiosulfate stability in gold leaching ...

01/05/2003  Ammonium thiosulfate is a noncyanide lixiviant for gold leaching. However, the major problem with this leaching method has been the high consumption of reagents. To leach a mild-refractory copper-bearing gold ore, the authors used a reagent combination of 0.3M (NH4)2S2O3, 0.03M CuSO4 and 3M NH3 at pH 10.2 for 24 hours. In the testing, thiosulfate consumption was 30 kg/t of ore.

thiosulfate leaching - Gold Refining Forum

19/05/2011  I have some questions about thiosulfate leaching. Has anyone here actually used thiosulfate for leaching gold ore,and had positive results,that can be repeatable as a real leaching process? Has anyone found a real working precipitation process to recover the gold,that works well,and is dependable? Also getting the gold out of the precipitates seems to be a real pain. Any real answers

Thiosulfate Leaching Process for Gold Extraction

Understanding gold thiosulfate leaching system plays a crucial role in order to effectively extract gold, in which the kinetics and equilibrium adsorption of thiosulfate, polythionates, gold thiosulfate and copper onto resin in resin-solution systems are taken into account. Process models associated with the adsorption of the species in resin-solution are also needed, which can be developed ...

Gold recovery from refractory gold concentrates by ...

Mohammadi et al. investigated ammoniacal thiosulfate leaching of refractory oxide gold ore, and they obtained maximum gold extraction of 55% (Mohammadi et al., 2017). Shen et al. had researched the direct thiosulfate leaching of gold from refractory ore, and they achieved gold recovery of only 70% (Shen et al., 2013). Li et al. studied the best conditions of roasting and oxidizing refractory ...

Associated Sulfide Minerals in Thiosulfate Leaching of ...

The effects of some associated minerals on thiosulfate gold leaching were studied through thermodynamic analysis and leaching experiments on composite ore samples containing various minerals and a reference silicate gold ore. In the leaching test on the reference gold ore, about 93% of gold was extracted within 3.0 hours. The presence of various amount of pyrite, pyrrhotite, chalcopyrite ...

The modes of gold loss in the calcium thiosulfate

The processing of gold is becoming more complicated due to the increasingly complex nature of the remaining gold-bearing ore bodies. This worldwide phenomenon is the driving force for the development of alternative technologies for the leaching and recovery of gold from so-called double refractory ores. Barrick Gold recently commercialized a unique calcium thiosulfate leaching plant to treat ...

Assessment of the Possibility of Hydrometallurgical ...

Research of noncyanide (thiosulfate) leaching of pure gold and concentrate of re-fractory gold-bearing oxidized ore in the autoclave was executed with the application of thiosulfate-copper and ammonium solutions. The reagent composition of the applied solution was as follows: 0.2 M Na2S2O3, 0.6 M NH3, 0.01 M CuSO4, 0.4 M Na2SO4. The total recovery of gold based on the analysis of the leaching ...

GOLD LECHING FROM A SAUDI ORE BY THE NONPOLLUTING ...

Gold leaching from a Saudi ore by the nonpolluting thiosulfate process 61 thiosulfate media other than copper and ammonia (Zhang et al., 2005; Chandra et al., 2005). Carbonaceous sulfide ores after oxidative pre-treatment are typically very easy to leach with thiosulfate, while complex metal sulfide ores are much more difficult to treat. The presence of various amount of pyrite, pyrrhotite ...

Improvement of thiosulfate stability in gold leaching ...

01/05/2003  Ammonium thiosulfate is a noncyanide lixiviant for gold leaching. However, the major problem with this leaching method has been the high consumption of reagents. To leach a mild-refractory copper-bearing gold ore, the authors used a reagent combination of 0.3M (NH4)2S2O3, 0.03M CuSO4 and 3M NH3 at pH 10.2 for 24 hours. In the testing, thiosulfate consumption was 30 kg/t of ore.

Gold recovery from refractory gold concentrates by ...

Mohammadi et al. investigated ammoniacal thiosulfate leaching of refractory oxide gold ore, and they obtained maximum gold extraction of 55% (Mohammadi et al., 2017). Shen et al. had researched the direct thiosulfate leaching of gold from refractory ore, and they achieved gold recovery of only 70% (Shen et al., 2013). Li et al. studied the best conditions of roasting and oxidizing refractory ...

Ammoniacal thiosulfate and sodium cyanide leaching of preg ...

gold leached from the carbonaceous matter to its initial gold content. Ammoniacal thiosulfate leaching of carbonaceous matter from autoclaved Goldstrike ore resulted in 90–100% solubilization of the gold initially present regardless of the preg-robbing behavior of the parent ore. For carbonaceous matters from non-autoclaved ores, ammoniacal thiosulfate leaching only solubilized about 40% of ...

ALTA MetBytes - What's Happening in Gold Ore Processing

CSIRO, Australia, has developed a thiosulfate-based reagent system for gold leaching that has excellent stability and shown broad applicability in the laboratory compared to the thiosulfate system commercially implemented by Barrick to treat double refractory gold ore following pressure oxidation at its Goldstrike Mine in Nevada, USA. The CSIRO ...

Associated Sulfide Minerals in Thiosulfate Leaching of ...

The effects of some associated minerals on thiosulfate gold leaching were studied through thermodynamic analysis and leaching experiments on composite ore samples containing various minerals and a reference silicate gold ore. In the leaching test on the reference gold ore, about 93% of gold was extracted within 3.0 hours. The presence of various amount of pyrite, pyrrhotite, chalcopyrite ...

The role of ligands and oxidants in thiosulfate leaching ...

the thiosulfate leaching of gold has been carried out at high temperatures up to 80°C and at oxygen partial pressures up to 100 psig (19). For example, a carbonaceous ore of gold grade 9-10 Au g/t contained 81.8% of gold associated with Gold Bulletin 2005 • 38/4 171 Figure 1 Effect of additives (0.1 M) on gold extraction and thiosulfate consumption during leaching of a mild-refractory ...

Assessment of the Possibility of Hydrometallurgical ...

Research of noncyanide (thiosulfate) leaching of pure gold and concentrate of re-fractory gold-bearing oxidized ore in the autoclave was executed with the application of thiosulfate-copper and ammonium solutions. The reagent composition of the applied solution was as follows: 0.2 M Na2S2O3, 0.6 M NH3, 0.01 M CuSO4, 0.4 M Na2SO4. The total recovery of gold based on the analysis of the leaching ...

Optimizing and evaluating the operational factors ...

08/12/2015  In recent years, thiourea, thiosulfate, chlorine and acid leaching methods have been developed as an alternative to cyanidation, ... The grade of gold ore is 3 ppm. Also, cyanide leaching is used to process gold in the Aghdareh mine . The main problem in extraction is achieving an acceptable separation of Au from its ore. Thus, the effects of the main controllable parameters affecting gold ...

sketches tables - UNIGE

conducted through wet, precrushed gold ore forming soluble gold chloride that could be washed out with water. The dissolved gold was eventually precipitated from the aqueous solution by ferrous sulphate. The rather common cyanide leach process is based on the selective solubility of gold in a weak cyanide solution. The chemical principles of gold leaching by sodium cyanide are the following ...

Thiosulphate Stability In Gold Leaching Process

gold ore to 62% with a thiosulphate consumption of 19kg/t.Sulphate addition could not ùnprove the thiosulphate stability significantiy, Gold Ieachmg at high pulp density (62%) produced the same gold extraction and greatiy reduced the thiosulphate consumption to 13kg/t. The mnieral content of the ore dso infiuenced the gold ...

(PDF) Thiosulfate leaching of gold—A review Mark

Hemmati et al. (1989) investigated the thiosulfate leaching of gold from carbonaceous ore that contained 2.5% organic carbon. The optimum conditions for gold extraction were found to be 35°C and 103 kPa oxygen over pressure, pH 10.5, 3M NH3 with a lixiviant containing 0.71M (NH4)2S203, 0.15M CuSO4 and 0.1M (NH4)2SO3.

Ammoniacal thiosulfate and sodium cyanide leaching of preg ...

gold leached from the carbonaceous matter to its initial gold content. Ammoniacal thiosulfate leaching of carbonaceous matter from autoclaved Goldstrike ore resulted in 90–100% solubilization of the gold initially present regardless of the preg-robbing behavior of the parent ore. For carbonaceous matters from non-autoclaved ores, ammoniacal thiosulfate leaching only solubilized about 40% of ...

The treatment of copper-gold ores by ammonium

The application of ammonium thiosulfate for the treatment of copper-gold ores has been investigated. Leaching studies were conducted with copper minerals, copper minerals with gold addition to solution and copper-gold samples of different copper and gold grades. The behaviour of thiosulfate, tetrathionate and sulfate in solution was studied using ion chromatography. The copper sulfide

Associated Sulfide Minerals in Thiosulfate Leaching of ...

The effects of some associated minerals on thiosulfate gold leaching were studied through thermodynamic analysis and leaching experiments on composite ore samples containing various minerals and a reference silicate gold ore. In the leaching test on the reference gold ore, about 93% of gold was extracted within 3.0 hours. The presence of various amount of pyrite, pyrrhotite, chalcopyrite ...

ALTA MetBytes - What's Happening in Gold Ore Processing

CSIRO, Australia, has developed a thiosulfate-based reagent system for gold leaching that has excellent stability and shown broad applicability in the laboratory compared to the thiosulfate system commercially implemented by Barrick to treat double refractory gold ore following pressure oxidation at its Goldstrike Mine in Nevada, USA. The CSIRO ...

Optimizing and evaluating the operational factors ...

08/12/2015  In recent years, thiourea, thiosulfate, chlorine and acid leaching methods have been developed as an alternative to cyanidation, ... The grade of gold ore is 3 ppm. Also, cyanide leaching is used to process gold in the Aghdareh mine . The main problem in extraction is achieving an acceptable separation of Au from its ore. Thus, the effects of the main controllable parameters affecting gold ...

sketches tables - UNIGE

conducted through wet, precrushed gold ore forming soluble gold chloride that could be washed out with water. The dissolved gold was eventually precipitated from the aqueous solution by ferrous sulphate. The rather common cyanide leach process is based on the selective solubility of gold in a weak cyanide solution. The chemical principles of gold leaching by sodium cyanide are the following ...

Using Plain Chute to Recovery Gold from Leaching

Based on the analysis of the properties of leaching residue of the gold flotation concentrate, through the application of newly-developed multi-layer automatic plain chute, it is possible to recover natural gold, pyrite and other metallic minerals from the leaching residue of flotation concentrate by using the gravity separation method, which enhanced the index of ore dressing recovery rate.

The Comparation of Cyanide and CNLITE Gold Leaching

17/01/2020  The Comparation of Cyanide and CNLITE Gold Leaching Reagent. With the call of the times, CNLITE eco-friendly gold ore dressing reagent that can be completely alternatives to the highly toxic sodium cyanide in gold leaching process appeared. 100% environmental protection. 100% safety.