1 Introduction
Brenda is part of Noranda Mining Company, located near Peaehland, British Columbia, Canada. 72km from the United States. 1500m above sea level. The copper - molybdenum deposit was discovered around 1935. In 1969, the capacity of mining and selection was 24 kt/d. After 1976, the capacity of mining and selection was over 30kt/d. Nissan amount of molybdenum metal 19.4t, the amount of copper metal 156.2t.
2. Deposits, ores and mining
The Brenda copper-molybdenum deposit is a hydrothermally induced low-grade porphyry copper-molybdenum deposit.
The ore body is produced by the Brenda rock strain on the western edge of the 458m wide, 790m long, from the Nigola contact 215~305m strong fracture zone, vertical depth of 275m. The ore reserves are 117.6 Mt.
The average grade of ore is 0.179% Cu, 0.046% Mo, and the main metal minerals are molybdenum ore and chalcopyrite. Molybdenite filled in the cracks, the cracks along a small amount pyrite, magnetite occasional companion. Galena in the form of small ore body.
3. Mineral processing technology
The crushing section adopts a three-stage and one-closed process, and the product size is -16mm. The coarse crushing machine uses a 1525×2260mm rotary crusher, and the middle crusher uses 2 sets of 2135mm standard cone crusher, 4 sets of 1352135mm short-head cone crusher, and 2.44×6.lm double-layer vibrating screen 5 sets of crushing screen. Segmentation. Grinding-mixing flotation section: as shown below.
Figure Brenda beneficiation process
Process: rod mill plus ball mill - two-stage grinding of the grading closed circuit unit. Product fineness 48% - 200 mesh, 37% ~ 35% + 60 mesh. One rough selection, one sweep, and three selected blend flotation processes. Obtained copper-molybdenum mixed concentrate.
The ore grade is 0.176% Cu, 0.047% Mo, the mixed concentrate grade is 20% Cu, 2% Mo, and the recovery rate of mixed concentrate is 88%~92%Cu, 82%~85%Mo. [next]
Equipment: The whole plant is divided into 4 grinding-mixing flotation series. Each series uses one 4.1×6.7m rod mill, one 4.1×6.7m ball mill and four ¢760mm hydrocyclones closed. The rough selection uses three sets of 5-slot Akitel-120 flotation machines, and the Denver DR type 24 flotation machine is selected.
Pharmacy: amyl xanthate (copper-mining mineral), fuel oil (catching copper ore), MIBC (foaming agent).
Copper-molybdenum sorting section: Concentrate of 4 mixed flotation series, merged into copper-molybdenum sorting. Sorting can be divided into three loops:
(1) Copper-molybdenum separation rough selection circuit: using one rough selection and one sweeping process, adding NaHS to suppress copper minerals, obtaining copper molybdenum concentrate by copper-suppressing molybdenum, sending loop (2); tailings feeding circuit (3).
(2) Molybdenum regrind selection circuit: Add a NaCN copper suppression with a period of re-grinding and twelve selected processes. When the lead is high, the latter paragraphs can also be added with a small amount of NaHS to suppress lead. High-grade molybdenum concentrate can be obtained through selection. However, flotation is also difficult to reduce copper and lead to the standard of high-quality molybdenum concentrate. For this reason, the molybdenum concentrate is leached with hot ferric chloride or the like to reduce copper and lead to 0.054% and 0.033%.
(3) Copper re-grinding selection circuit: The tailings of the copper-molybdenum separation roughing circuit are sent to the circuit. First, it is concentrated and then ground to 90%-325 mesh, then enters three selections, one sweeping operation. , obtained high-grade copper concentrate. The recovery of copper and molybdenum in the entire separation circuit is about 97% to 98.5%.
4. Leaching of flotation molybdenum concentrate
Unlike high-quality molybdenum concentrates, Claymaxes stipulates high-quality concentrate standards: MoS 2 95%, Cu <0.15%, and Pb <0.05%. However, the molybdenum concentrate recovered from the by-product of copper-molybdenum ore is often high in copper, exceeding 0.5%, and sometimes lead is also excessive.
The price difference between high quality and non-high quality molybdenum concentrate is quite large. On July 1, 1975, the price of Claymax's high-quality molybdenum concentrate was 2.43 US dollars per pound of molybdenum, while the non-precision molybdenum concentrate containing copper and lead exceeded 2 to 2.36 US dollars per pound of molybdenum. The spread is 2.5%~17%.
It is difficult for the flotation method to obtain high-quality products for copper-molybdenum ore. To this end, Noranda researched and extracted the method of extracting molybdenum concentrate such as hot ferric chloride, and obtained a patent, which was promoted as the “Silenda” method. The mechanism of leaching has been introduced in the previous chapter.
Leachate ratio of CuCl 2 1%, FeC1 3 10 %, CaCI 3 30% ( or NaCI), HCl1% ~ 5% .
Leaching conditions: about 105 ° C, leaching for 2 h.
The lean leaching liquid passes through the chlorine gas to regenerate FeCl 3 : 2FeC1 2 + C1 2 → 2FeCI 3 .
Chemical consumption and cost (calculated in 1974): FeCl 3 (anhydrous) consumption 44.5kg / t molybdenum concentrate, cost 15.2 US dollars / t molybdenum concentrate; CaCl 2 (anhydrous) consumption 113.5kg / t molybdenum concentrate , cost 21.25 US dollars / t molybdenum concentrate; Cl 2 (anhydrous) consumption 5.5kg / t molybdenum concentrate, cost 1.16 US dollars / t molybdenum concentrate.
Leaching effect: Cu, Pb leaching rate of 98%, Ca leaching rate of 76%.
Pre-dip grade: 54.97% Mo, 0.32% Cu, 0.38% Pb.
After immersion grade: 55.89% Mo, 0.054% Cu, 0.033 Pb.
5. Dressing agent consumption
Pharmacy
Types of
Dosing point
Consumption
(g/t ore)
(kg/t mixed)
Amyl xanthate
Collector
Mixed flotation section
5.45
Fuel oil
Molybdenum collector
Mixed float + molybdenum selection
15.44
MIBC
Foaming agent
18.6
NaHS
Inhibitor
Copper-molybdenum separation
86.7
5.22 (mixed concentrate meter)
NaCN
Inhibitor
9.5
1.38 (mixed concentrate meter)
FeCl 3
Oxidant
Molybdenum concentrate leaching section
28.1
44.5 (molybdenum concentrate meter)
CaCl 2
Molybdenum concentrate leaching section
45.9
113.5 (molybdenum concentrate meter)
6. Sorting indicators
The ore is 30kt/d, grade 0.167% Cu, 0.045% Mo. The molybdenum concentrate grade is 55.89% oMo, 0.054% Cu, 0.033% Pb, and the molybdenum recovery rate is 80.33%. Copper concentrate grade 28.08% Cu, 0.203% Mo, copper recovery rate 86.71%. Yield: molybdenum concentrate 19.7t / d molybdenum metal amount, copper concentrate 156.2t / d copper metal amount.

Edger Rolls

Edger rolls

Description: Also called as Vertical Rolls, the center line of the rolls vertically to the horizontal line, used for descaling and edging.( section mill, H beam mill, angel steel mill, channel steel mill, deformed bar mill or rebar mill)

Material: Adamite, alloy adamite, alloy cast steel, alloy cast iron or as per the customer`s requirement.

Barrel Diameter: 1500mm maximum

Unit weight: 25mt/pc

Type: Single rolls, double pouring cast rolls.

Casting: Static casting, centrifugal casting.

Heat treatment: annealing, normalizing, quenching, and tempering.

Edger Rolls,Shaped Mill Edger Rolls,Section Mill Vertical Rolls,Alloy Cast Iron Edger Rolls

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