Gold bars produced from a Xinhai processing circuit

Gold: four routes, chosen by the ore rather than by habit

Free milling, refractory, alluvial or low grade, the route follows the test result. Xinhai has delivered gold plants across West Africa, East Africa and Central Asia.

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Process route

Which route applies depends on gold liberation, carbon content and the presence of sulphides. Test work settles it before the flowsheet is drawn.

01

Crushing and grinding

Jaw and cone crushing followed by ball milling in closed circuit with hydrocyclones, to the liberation size the test work identifies.

02

Gravity recovery

Where coarse free gold is present, centrifugal concentrators and shaking tables recover it before leaching, which reduces reagent consumption.

03

Flotation or leaching

Sulphide associated gold is floated to a concentrate. Free milling ore goes to cyanide leaching, either carbon-in-pulp or carbon-in-leach, where adsorption runs alongside leaching.

04

Desorption and refining

Loaded carbon is stripped in a desorption and electrowinning system, then the carbon is regenerated and returned to the circuit.

05

Tailings handling

Thickening and filtration, with dry stacking where water balance or regulation requires it.

Equipment in this circuit

Manufactured at our own bases and matched to the circuit capacity, not bought package by package.

PE series jaw crusher

Jaw crusher

PE series for primary crushing and PEX series for secondary and fine crushing.

Wet ball mill

Ball mill

Wet grid mills for primary grinding and overflow mills for secondary grinding.

Continuous gold centrifugal concentrator

Centrifugal concentrator

Continuous recovery of free gold and other heavy minerals.

JJF mechanical flotation cell

Flotation cells

SF, JJF, XCF, KYF and BF machines up to 320 m3, plus flotation columns.

Double impeller gold leaching agitation tank

Leaching and adsorption tank

Double impeller tanks up to 20 m diameter for CIP and CIL circuits.

Gold desorption and electrowinning system

Elution and electrowinning

Desorption, electrowinning and carbon regeneration as one package.

Reference projects

Figures are those reported for these projects in the Xinhai project and test brochures.

Guinea

3,000 t/d gold mine and plant, 1.2 g/t feed, overall recovery around 93%

EPC+M+O
Kyrgyzstan

4,000 t/d gold carbon-in-pulp plant

Plant scope
Zimbabwe

500 t/d gold project, mining and processing optimised, local team trained

EPC+O
Ghana

1,000 t/d gold processing plant

Plant scope
Tanzania

1,200 t/d gold processing plant

Plant scope
Burundi

1,200 t/d gold processing plant

Plant scope
Sudan

700 t/d rock gold processing plant

Plant scope
Mali

150 t/d gold processing plant

Plant scope

Common questions

When is CIL better than CIP?
Carbon-in-leach adsorbs gold while leaching proceeds, which suits ores with preg-robbing carbonaceous material and shortens the circuit. Xinhai reports recovery of up to 99% on ores suited to CIL. Carbon-in-pulp keeps leaching and adsorption separate, which is simpler to operate on clean, free milling ore.
Can gravity recovery be added to an existing plant?
Often yes. Centrifugal concentrators and shaking tables ahead of leaching recover coarse free gold and reduce cyanide consumption, and they can be retrofitted into the grinding circuit.
What test work does a gold project need before design?
Element and phase analysis to establish how the gold occurs, then bottle roll or leach tests, flotation tests where sulphides are present, and a pilot run before a large plant is committed. See our test work service.
Does Xinhai operate gold plants as well as build them?
Yes. The Guinea project is an EPC+M+O contract where Xinhai carried the mining and processing operation as well as the build.

Related

Test work first

Leach, flotation and gravity test work on your sample decides which of the four routes applies.

Test work

Guinea case study

3,000 t/d gold mine and plant delivered and operated under one contract.

Case study

Operation contracts

Eight cooperation models for running the mine and the plant after commissioning.

Operation

Send the assay and the tonnage target for your Gold project.

We start with test work on your sample, then size the circuit around the result. Tell us where the project stands and what you need next.

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