Mining industry recovery may bolster Australia’s economy again
Rio Tinto’s iron ore operations in Australia’s Pilbara region. (Image courtesy of Rio Tinto)
Australia’s resource industry is set to aid the economic recovery once again as higher prices and expansion plans assist the nation emerging from its coronavirus lockdown.
Mining accounts for nearly 6% of gross domestic product but plays an outsized role in national income, delivering dividends to pension funds and funds for government coffers. Iron ore, the nation’s biggest export, has broken $100 a ton amid off-shore supply concerns, providing a timely budget boost.
“After declining for several years, mining capex is poised to lift over 2H 2020 and beyond. The precursors for a pickup in investment, such as higher prices and elevated levels of exploration expenditure, remain in place, and could see investment lift beyond replacement levels over coming years.”
James McIntyre, economist
The government’s most recent budget numbers from December were based on iron ore falling to $55 a ton, excluding freight, by the June quarter of 2020. The government gains around A$3.7 billion for every $10 in excess of this estimate in the year to June 2021, which will assist the budget position following the massive fiscal injection.
In 2009, Australia dodged recession and rocketed into recovery as China dropped more than $500 billion of stimulus into its own economy spurring a mining investment boom Down Under. China’s stimulus package is much smaller this time — and Australia is already in recession — but the path ahead could prove similar.
Strained relations
While, the Australia-China relationship is in stormy waters following Prime Minister Scott Morrison’s calls for an independent probe into the origins of the coronavirus, key bulk commodities have been insulated from the spat because of the dearth of high-quality suppliers elsewhere.
China has fired warning shots at Australia with tariffs on barley and the suspension of shipments from some abattoirs. Tensions escalated Friday when China’s Ministry of Culture and Tourism published a statement on its website saying that Chinese tourists to be on alert for their safety and not travel to Australia.
Andrew Ticehurst, a rates strategist at Nomura Holdings Inc., is worried that the tensions could limit the upside.
“It won’t be as strong as 2009 when there was a pipeline of projects, but it’s a positive when you put together mining investment, the terms of trade and our exposure to China.”
Shane Oliver, chief economist at AMP Capital Investors Ltd.
“Iron ore is a genuine bright-spot for Australia,” he said. “However, given the deterioration in Australia-China trade relationship, China may not wish to be seen as ‘rewarding’ Australia too much, and higher iron ore imports could be offset by reduced imports of other commodities, goods and services.”
Further assisting domestic iron ore producers, Australia’s key rival, Brazil, has been forced to close mine sites as the nation battles Covid-19.
Rio Tinto Group, the world’s No. 2 miner, in November lifted planned spending on new iron ore mines in Australia to $4 billion, while BHP Group and Fortescue Metals Group Ltd. are both investing more than $3 billion apiece in their own developments. The mines are largely aimed at replacing retiring facilities to sustain exports, though will offer options to boost shipments.
Coal and gold producers are also spending money on new projects in Australia and exploration budgets are rising. Australian gold miners — on track to become the top producer — are resuming a pandemic-disrupted exploration spree amid surging prices.
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-12-2020