Zambia’s CEC to discontinue power supply to Konkola Copper Mines
Zambia’s Copperbelt Energy Corp (CEC) will stop supplying power to Vedanta’s local unit Konkola Copper Mines (KCM) from Monday, it said after talks on an extension to their supply agreement broke down over debt owed to CEC.
Zambia’s Energy Minister Mathew Nhkuwa told Reuters that KCM would now receive its power directly from state-owned utility Zesco, which has previously sold electricity to CEC for onward supply to KCM.
Nkhuwa said the bulk electricity supply agreement between Zesco and CEC, which expired on March 31, would not be renewed.
The power supply agreement between CEC and KCM also came to an end on March 31 and was extended through mutual agreement only as far as May 31, CEC said in a statement on Sunday. KCM owes the energy company $132 million, CEC said.
“Negotiations for its further extension have broken down, despite CEC’s best efforts in good faith towards securing a new contract,” the statement said.
A KCM statement statement said that, after the expiry of its contract with CEC, the company had entered into another agreement with Zesco, effective June 1.
“We expect a seamless transition in the supply of power from CEC to Zesco and any interference or restriction will be an act of sabotage,” KCM said.
In trying to agree the new contract, CEC sought to resolve KCM’s outstanding $132 million debt and also obtain a firm commitment from KCM on timely payment of future electricity charges, it said.
CEC said it had informed KCM that its supply will be discontinued, adding that this was the only option available after the failed talks.
“Due care has been taken to make certain that the process of discontinuing supply ensures the safety of personnel and equipment and preserves the integrity of the mine,” CEC said.
India’s Vedanta owns about 80% of KCM.
While Zesco will now transport power to KCM, it will still travel through CEC power lines. Nkhuwa said that CEC would be breaking the law if it refused to transport the power.
“I issued a statutory instrument on Friday, declaring the CEC lines a common carrier. CEC is therefore obliged to transport the power from Zesco to KCM at a fee,” Nkhuwa said.
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