Prosecutors ask court to remove Vale managers

Federal prosecutors in Brazil’s Minas Gerais state are seeking a court order for miner Vale SA to replace executives they accuse of disregarding safety methods in the aftermath of two deadly mining disasters.

They have asked a court in Minas Gerais to name an interventor to take charge of Vale’s safety program, according to a statement the prosecutors’ office shared with Reuters.

The request would require approval by the court.

Vale said in a statement it has not been formally notified and will respond in court when it is, adding that it had learned about the developments via the media.

Prosecutors said they want the interventor to identify within 15 days executive managers and other top management members who should be replaced in a corporate reshuffle.

The interventor would be charged with drawing up a plan to reshape Vale’s governance system to comply with international standards for disaster prevention, the prosecutors said.

The governance system currently adopted by the mining company has generated extensive damage to society and to the environment, the prosecutors say.

The so-called Brumadinho task force of prosecutors was set up after a January 2019 disaster at a Vale mine where a dam burst, killing 270 people. An earlier dam burst occurred in 2015 at a mine in Mariana owned jointly by Vale and BHP Group Ltd causing Brazil’s worst environmental disaster.

The prosecutors said that, contrary to what Vale has stated and the data it discloses, it has developed over time an internal culture that is unable to recognize safety threats.

The company acts on “corporate irresponsibility,” they say, and needs a reshuffle to change its culture to start taking preventative safety measures.

Earlier on Wednesday, Vale said it put on watch three dams and three dikes after failing to meet the security requirements during regular reviews by third party auditors.

Safety rules

Brazil’s Senate passed a bill on Wednesday that tightens the safety rules and inspection for dams in the mining industry, setting fines of up to 1 billion reais ($187 million) for failure to comply.

The legislation reinforces the prohibition of the use of upstream dams for tailings ponds, like one that burst in January 2019 killing 270 people at the Brumadinho mine.

The bill goes to President Jair Bolsonaro’s desk to be signed into law.

“Dams of this type will have until February 2022 to be de-commissioned and changed under a security and demobilization plan,” said Senator Antonio Anastasia, the bill’s sponsor in the upper chamber.

A first version of the law presented by Anastasia in 2019 set fines of up to 10 billion reais, but that figure was reduced in committee.

The bill also bans the construction of any tailings dams close to communities that are within 10 kilometers distance or a 30-minute drive below the dam.

Upstream dams were banned in February 2019 and companies were given deadlines to decommission dozens of similar structures in the country. At first, the National Mining Agency set until 2021 for companies to dissemble the dams.

In August 2019, the regulatory agency extended the deadline by almost six years, to 2022, 2025 and 2027, depending on the size of the structure.

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（%）
Name	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+2

0+3

0+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（%）
Name	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）

MicrostructureHigh Chrome Alloy Liner≥58≥3.5M+C+AMiddle Chrome Alloy Liner≥48≥10M+CLow Chrome Alloy Liner≥45≥15M+C+PM- MartensiteC – CarbideA-AusteniteP-Pearlite

Product specification

Size	Hole Dia.（mm） Liner Length（mm）
Size	≤40	≥40	≤250	≥250
Tolerance	+2

0+3

0+2+3

Cr-Mo Alloy Steel

Qiming 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（%）
Code	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

White iron liner is recommended to be using at low impact working condition such as :

1. Belt conveyor liner for the Mining industry.

2. Cement plant ball mill.

3. Chemical industry ball mill.

Chemical Composition

Name	Chemical Composition(%)
Name	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: Sep-04-2020