Biggest copper nation has an optimistic take on hectic news flow
Copper traders are being bombarded with possible price drivers right now — from $1 trillion in U.S. infrastructure spending to a second wave of Covid-19 in China. For Chile’s official forecaster, the upshot is cautiously optimistic.
Prices probably will average more than $2.50 a pound this year, according to Marco Riveros, who heads government agency Cochilco. So far this year, the average has been just below that level.
With demand supported by a recovery in Europe and President Trump’s infrastructure proposal, there’s incentive for Chilean mines to continue operating at near capacity levels, Riveros said in an interview Tuesday.
In a country that produced 5.8 million tons of the red metal last year, Covid-19 disruptions could cost as few as 75,000 tons or as many as 400,000 tons, the agency said. Somewhere in the middle of that range, about 200,000 tons, would be a reasonable expectation, he said.
So many variables make precise short-term predictions difficult. Companies are constantly reformulating their mining plans as they chase productivity gains while operating with reduced workforces. As more workers fall ill, Chilean unions are calling for limiting operations.
While health has to be the top priority and some mines may struggle to maintain output, Cochilco’s vision is for the industry to be viewed with optimism, Riveros said.
“Particularly in Chile, mining has always had the ability to push economic development, and in this case, economic recovery forward,” he said.
In a bid to ease labor tensions and keep mines running, the government is working on ways to improve Covid-19 transparency.
Mining Minister Baldo Prokurica is looking into disseminating infection data from local health authorities, rather than just from companies. The government may also report the results of audits into how well mines are complying with virus-fighting protocols, he said in an interview Monday.
In contrast with neighboring Peru, Chile opted to continue mining as the virus hit, implementing safety measures and demobilizing non-essential staff without sacrificing much output. For Prokurica, it’s a balancing act of keeping workers healthy and much needed export revenue flowing.
“We are going to do everything in our capacity so the country can assure workers of their jobs, and at the same time have continuity, while protecting the health and safety of our workers,” he said.
Tensions ratcheted up last week after a worker at state-owned Codelco’s Chuquicamata mine died of the disease. The minister dispatched additional inspectors to monitor the situation at mines, with 1,600 evaluations conducted so far.
On the weekend, seven groups representing workers and contractors issued a call for the government to reevaluate continuing mining operations. Late Tuesday, the Federation of Copper Workers said union leaders weren’t allowed to access the Chuquicamata mine to inspect protocol compliance in the latest example of management’s “arrogant conduct.”
Prokurica said the industry is taking extraordinary measures to safeguard staff, including testing, distancing and demobilizing about half the total workforce. While infections are rising in the nation, mining has done better than other industries, with just 0.5% of the workforce falling ill, he said.
“There is no normalcy in the copper industry right now,” Prokurica said. “We are in the most difficult phase of the pandemic in Chile.”
Ball Mill Liner Material Selection
Different crushed material, different working conditions need different material liners to suit. Also, the coarse grinding compartment and fine grinding compartment need different material liners.
H&G Machinery supplies the following material to cast your ball mill liner:
Manganese Steel
The manganese content of the high manganese steel ball mill lining plate is generally 11-14%, and the carbon content is generally 0.90-1.50%, most of which are above 1.0%. At low impact loads, the hardness can reach HB300-400. At high impact loads, the hardness can reach HB500-800. Depending on the impact load, the depth of the hardened layer can reach 10-20mm. The hardened layer with high hardness can resist impact and reduce abrasive wear. High manganese steel has excellent anti-wear performance under the condition of strong impact abrasive wear, so it is often used in wear-resistant parts of mining, construction materials, thermal power, and other mechanical equipment. Under the conditions of low impact conditions, high manganese steel cannot exert the characteristics of the material because the work hardening effect is not obvious.
Chemical Composition
| Name | Chemical Composition（%） | |||||||
| C | Si | Mn | Cr | Mo | Cu | P | S | |
| Mn14 Mill Liner | 0.9-1.5 | 0.3-1.0 | 11-14 | 0-2.5 | 0-0.5 | ≤0.05 | ≤0.06 | ≤0.06 |
| Mn18 Mill Liner | 1.0-1.5 | 0.3-1.0 | 16-19 | 0-2.5 | 0-0.5 | ≤0.05 | ≤0.06 | ≤0.06 |
Mechanical properties and metallographic structure
| Name | Surface Hardness（HB） | Impact value Ak（J/cm2） | Microstructure |
| Mn14 Mill Liner | ≤240 | ≥100 | A+C |
| Mn18 Mill Liner | ≤260 | ≥150 | A+C |
| C -Carbide | Carbide A-Retained austenite | Austenite | |||
Product specification
| Size | Hole Dia.（mm） | Liner Length（mm） | ||
| ≤40 | ≥40 | ≤250 | ≥250 | |
| Tolerance | +20 | +30 | +2 | +3 |
Chrome Alloy Steel
Chromium alloy cast iron is divided into high chromium alloy cast iron (chromium content 8-26% carbon content 2.0-3.6%), medium chromium alloy cast iron (chromium content 4-6%, carbon content 2.0-3.2%), low chromium Three types of alloy cast iron (chromium content 1-3%, carbon content 2.1-3.6%). Its remarkable feature is that the microhardness of M7C3 eutectic carbide is HV1300-1800, which is distributed in the form of a broken network and isolated on the martensite (the hardest structure in the metal matrix) matrix, reducing the cleavage effect on the matrix. Therefore, the high-chromium alloy liner has high strength, ball mill toughness, and high wear resistance, and its performance represents the highest level of current metal wear-resistant materials.
Chemical Composition
| Name | Chemical Composition（%） | |||||||
| C | Si | Mn | Cr | Mo | Cu | P | S | |
| High Chrome Alloy Liner | 2.0-3.6 | 0-1.0 | 0-2.0 | 8-26 | ≤3.0 | ≤1.2 | ≤0.06 | ≤0.06 |
| Middle Chrome Alloy Liner | 2.0-3.3 | 0-1.2 | 0-2.0 | 4-8 | ≤3.0 | ≤1.2 | ≤0.06 | ≤0.06 |
| Low Chrome Alloy Liner | 2.1-3.6 | 0-1.5 | 0-2.0 | 1-3 | 0-1.0 | ≤1.2 | ≤0.06 | ≤0.06 |
Mechanical properties and metallographic structure
| Name | Surface（HRC） Ak（J/cm2） | Microstructure | ||||
| High Chrome Alloy Liner | ≥58 | ≥3.5 | M+C+A | |||
| Middle Chrome Alloy Liner | ≥48 | ≥10 | M+C | |||
| Low Chrome Alloy Liner | ≥45 | ≥15 | M+C+P | |||
| M- Martensite | C – Carbide | A-Austenite | P-Pearlite | |||
Product specification
| Size | Hole Dia.（mm） Liner Length（mm） | |||
| ≤40 | ≥40 | ≤250 | ≥250 | |
| Tolerance | +20 | +30 | +2 | +3 |
Cr-Mo Alloy Steel
H&G Machinery uses Cr-Mo alloy steel to cast ball mill liner. This material based on Australia standard, (AS2074 Standard L2B, and AS2074 Standard L2C）it’s provides superior impact and wear resistance in all semi-autogenous milling applications.
Chemical Composition
| Code | Chemical Elements（%） | |||||||
| C | Si | Mn | Cr | Mo | Cu | P | S | |
| L2B | 0.6-0.9 | 0.4-0.7 | 0.6-1.0 | 1.8-2.1 | 0.2-0.4 | 0.3-0.5 | ≤0.04 | ≤0.06 |
| L2C | 0.3-0.45 | 0.4-0.7 | 1.3-1.6 | 2.5-3.2 | 0.6-0.8 | 0.3-0.5 | ≤0.04 | ≤0.06 |
Physical Property & Microstructure
| Code | Hardness（HB） | Ak（J/cm2） | Microstructure |
| L2B | 325-375 | ≥50 | P |
| L2C | 350-400 | ≥75 | M |
| M-Martensite, C-Carbide, A-Austenite, P-Pearlite | |||
Ni-hard Steel
Ni-Hard is a white cast iron, alloyed with nickel and chromium suitable for low impact, sliding abrasion for both wet and dry applications. Ni-Hard is an extremely wear-resistant material, cast in forms and shapes which are ideal for use in abrasive and wear environments and applications.
Chemical Composition
| Name | C | Si | Mn | Ni | Cr | S | P | Mo | Hardness |
| Ni-Hard AS2027 Gr Ni Cr 1-550 | 3.2-3.6 | 0.3-0.8 | 0.2-0.8 | 3.0-5.0 | 1.5-3.0 | ≤0.12 | ≤0.15 | ≤0.5 | 550-600HBN |
| Ni-Hard AS2027 Gr Ni Cr 2-550 | 2.8-3.2 | 0.3-0.8 | 0.2-0.8 | 3.0-5.0 | 1.5-3.0 | ≤0.12 | ≤0.15 | ≤0.5 | 500-550HBN |
| Ni-Hard AS2027 Gr Ni Cr 2-550 | 3.2-3.6 | 1.5-2.2 | 0.2-0.8 | 4.0-5.5 | 8.0-10.0 | ≤0.12 | ≤0.15 | ≤0.5 | 630-670HBN |
White Iron Steel
Chemical Composition
| Name | Chemical Composition(%) | |||||||
| C | Si | Mn | Cr | Mo | Cu | P | S | |
| White Iron Steel Liner | 2.0-3.3 | 0-0.8 | ≤2.0 | 12-26 | ≤3.0 | ≤1.2 | ≤0.06 | ≤0.06 |
Physical Property & Microstructure
| Name | HRC | Ak(J/cm2) | Microstructure |
| White Iron Steel Liner | ≥58 | ≥3.5 | M+C+A |
| M-Martensite C- Carbide A-Austenite | |||
If you have a special material inquiry, please contact our engineer to service you!
Nick Sun NICK@XZHUAGANG.COM
Post time: Jun-19-2020