Tag Archives: silica

Cedric Minería selects CDE EvoWash wet processing tech for Buin sand, gravel ops

Chilean mining and aggregates company, Cedric Minería, has announced a major overhaul of its aggregates business following a significant investment in advanced wet processing technology from CDE, the Belfast-based company says.

The family business, which expanded into aggregates production in 2003, has revealed plans for a new wet processing solution at its Buin operation.

Established in 1981, Cedric Minería specialised in the production of calcium carbonate and sulphur products before diversifying its interests and launching its silica operation, Mina Nancy, near the city of Calama in Antofagasta Region.

It soon secured listing as a strategic supplier of silica to state-owned copper mining company Codelco for its copper smelting plant in Chuquicamata, northern Chile.

Following the success of its silica business, Cedric Minería soon after commissioned its first aggregates processing plant in Buin which supplies the local market with a range of washed sand and gravel products for pre-cast concrete, asphalt, pipe bedding and more.

This summer, CDE will commission the EvoWash™ sand wash plant and an AquaCycle™ water management system at the company’s Buin site, replacing their existing washing screws.

Using CDE cyclone technology, the new plant will enable Cedric Minería to produce two grades of high quality, in-spec fine sands: 0-5 mm and 0-8 mm.

A compact, modular sand washing system, CDE’s EvoWash screens and separates the smaller sand and gravel fractions through an integrated high-frequency dewatering screen, sump and hydrocyclones which provide control of silt cut points and eliminates the loss of quality fines with significant commercial value.

An alternative to water extraction and the costly process of pumping water to the plant, CDE’s AquaCycle significantly reduces costly water consumption by ensuring up to 90% of process water is recycled for immediate recirculation, the company says. It helps to accelerate return on investment by maximising production efficiency, minimising the loss of valuable fines and reducing water and energy costs. A single, compact and user-friendly unit, it can be applied to high and low tonnages across many market sectors.

Cedric Minería owner, Cedric Fernández, says the investment in CDE technology is a significant step forward for the company.

“We’re making a huge technological leap forward with this new plant. Cedric Minería branched into the aggregates business almost two decades ago and throughout that time we have operated a traditional system,” Fernández said. “The existing plant has served us well, but we need a modern solution that is future-ready. Our latest investment in CDE wet processing technology represents the beginning of a new chapter for our company.”

Fernández says the COVID-19 pandemic had a significant impact on the construction industry but anticipates strong future demand for sand and aggregates to support the country’s public works investments.

CDE Business Development Executive, Gustavo Brasil, says older technology is very much under the spotlight for materials processors as they work to remedy inefficiencies.

“Recognising the limitations of the existing setup, the team at Cedric Minería are setting out on an ambitious transformation project to replace a traditional processing plant with a much more advanced and efficient technological solution,” he said.

The CDE solution engineered for Cedric Minería will revolutionise its current process, he added.

“CDE’s Evowash solution will enable Cedric Minería to produce superior fine sands with less moisture content while the AquaCycle water management system will deliver massive efficiency gains by recycling process water and driving down operational costs,” he said.

COREM, Steinert ore sorting tests present opportunities for Cartier at Chimo gold project

Cartier Resources says ore sorting tests carried out by COREM and Steinert US on mineralised samples from the Chimo Mine property, in Quebec, Canada, have indicated gold grades could increase substantially with the use of the pre-concentration technology.

Gold from Chimo is present in two types of mineralised facies: i) quartz veins with coarse visible gold grains having an affinity for the gravity concentration of gold at the mill and ii) zones of silica-rich mafic rocks associated with non-refractory arsenopyrite having an affinity for the flotation of a concentrate of arsenopyrite for gold recovery at the mill.

To perform the sorting tests, rocks representative of the two mineralised facies, made up of the following six mineralogical facies, were first selected for static recognition of each of the facies by the sensors of the sorter:

  • Gold-bearing quartz veins;
  • Gold-bearing silica;
  • High grade gold-bearing arsenopyrite;
  • Medium grade gold-bearing arsenopyrite;
  • Low grade gold-bearing arsenopyrite; and
  • Mafic waste rock.

The detection sensors of the industrial sorter at COREM in Quebec, Canada, were the RGB camera using the optical properties of reflection, brightness and transparency to locate quartz and silica and the X-ray Transmission sensor using the volumetric property of atomic density to locate arsenopyrite. The two sensors adequately recognised the six mineralogical facies associated with the mineralisation, with dynamic calibration tests of the sorter with the moving conveyor making it possible to sort, one at a time, 2 kg samples of each of the facies, Cartier said.

The results of this first test at COREM showed the first three sorts (on a total of eight sorts) concentrated 99.1% of the gold contained in 44.4% by mass of material mass for a grade of 56.3 g/t Au, representing a percentage increase of 223% in gold content over sorter feed. The reject, representing 0.9% by mass of material, contained only 0.4 g/t Au.

The sorter was then ready to perform sorting tests on the 105.7 kg production sample, representative of the mineralised facies at an average grade of 2.16 g/t Au. This content was obtained by including 20% by mass of material with zero grade of gold, simulating dilution in the stopes. COREM’s sorting plan separated 53.9% by mass of the material in the form of a preconcentrate at an average grade of 3.68 g/t Au, representing an increase of 170% in the gold grade compared with the sorter feed. The waste disposal, separated from the mineralisation, represented 46.1% by mass of material at an average grade of 0.38 g/t Au.

Sorting tests carried out with Steinert in Kentucky using a Steinert KSS FLI XT machine with XRT, colour, laser, and induction sensors yielded comparable results.

A 80.69 kg production sample, representative of the mineralised facies at an average grade of 2.13 g/t Au, to which 20% by mass of material at zero grade of gold was added mathematically, representing the dilution in the workings, was used for testing. The new calculated diluted grade was 1.55 g/t Au.

Calculation of the results revealed that 51% by mass of the dilute grade material could be separated as a preconcentrate at an average grade of 2.72 g/t Au, representing a 175% increase in gold grade compared with the sorter feed. The waste disposal, which would be separated from the mineralisation, would represent 49% by mass of material at an average grade of 0.36 g/t Au.

Sorting tests with COREM were carried out following these tests to validate that the 20% of dilution material at zero grade of gold, mathematically added, could physically be effectively separated by the sorter, Cartier said.

The sorting tests carried out by both COREM and Steinert US were comparable, with these results providing prospects for increasing the value of the resources with ore sorting technology.

The objective of the industrial sorting of the mineralisation is to increase the grade of the preconcentrated material preceding the milling operations, which allows an increase in the recovery rate at the mill, reduces transport costs to the mill, reduces milling costs, reduces the costs of environmental restoration of mine tailings, and reduces the environmental footprint of mine tailings and, consequently, increases the social acceptability of the mining project, Cartier said.

The most recent resource estimate from Chimo included 6.6 Mt at an average grade of 3.21 g/t Au for a total of 684,000 oz of gold in the indicated category and 15.2 Mt at an average grade of 2.77 g/t Au for a total of 1.36 Moz of gold in the inferred category.