Iamgold suspends operations in Suriname amid covid-19 cases
Canadian gold miner Iamgold on Tuesday halted operations at its Rosebel gold mine in Suriname as a workers union issued a stop work order after seven employees tested positive for the novel coronavirus.
The company said the infected employees were quarantined and it was taking steps to disinfect the workers’ living and work areas, but the union used one of its preventative measures as the basis to stop work.
“Due to Union resistance to the implementation of covid-19 control measures, we are suspending operations until the appropriate controls are in place to protect the safety of all employees,” the company said in a statement.
Miners globally had temporarily suspended production at some of their mines due to the covid-19 pandemic and government-mandated lockdowns to curb the spread of the virus.
Iamgold said it had implemented social distancing rules, sanitary measures and reduced its on-site staff at the mine after the outbreak.
Union spokesman Otmar Biswane told a local radio station on Tuesday the safety measures were not enough.
“It’s not that there are no provisions at all, but the provisions are not such that you can accommodate so many people in one camp and just want to run 100% production right through that pandemic,” he said.
The Rosebel gold mine is majority owned by the Canadian miner, while the South American country’s government holds a 5% stake.
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