1, the profile
The Claymax Mine is owned by Claymax, a subsidiary of Cymax Co. It is an old factory with nearly 70 years of mining history, and it is the largest manufacturer with the largest molybdenum production and advanced production indicators.
Claymax is located in the middle of the Rocky Mountains in Colorado, USA, at the top of the Fremont Pass, at an altitude of 3,400m. 93km west of Denver.
In 1879, Charles Jason discovered molybdenite in the Butler Mountain; in 1916, Claymax began exploration and development; in 1918, the first 250t/d plant was completed and put into production; The amount is 30 kt ore; in 1973, the open pit mine was put into operation, with a total capacity of 48 kt/d.
As of July 1, 1975, 335 Mt of ore was produced from the Claymax deposit, producing 680 kt of molybdenum.
2. Deposits, ores and mining
The Claymax Molybdenum deposit is a well-mineraled giant quartz -porphyry reticular molybdenum deposit. According to the June 1, 1975 data, the Claymax molybdenum ore reserves are estimated to be above 505 Mt. By the end of 1983, the mine to maintain reserves of 375Mt of ore, which is a recoverable amount of molybdenum metal was 626kt. Among them, open pits accounted for 36%, the average grade of ore was 0.18% Mo; the pit mining area accounted for 64%, and the average ore grade was 0.20% Mo. The mineral components in the ore are shown in the table. The ore also contains a small amount of cassiterite and monazite.
Table 1 Main mineral composition of molybdenum ore
mineral | quartz | Feldspar | Plagioclase | Pyrite | Black mica | Molybdenite | Wolfram ore |
content(%) | 60~70 | 20 | 5 | 3 | 2 | 0.34 | 0.06 |
In general, quartz-feldspar, muscovite-sericite and clay content vary greatly, which is caused by ore bodies in different altered ore layers. In terms of metallic minerals, ore with increasing depth, pyrite, tungsten, manganese tends to decrease, brass tends to increase ore, molybdenite remained relatively stable.
Molybdenite is the main metal mineral of Claymax. The content of molybdenum oxide is very small, mainly in goethite, followed by jarosite. Molybdenum is the product of weathering of the oxide coating and the oxide-sulfide transition zone. Molybdenum ore is present in quartz-molybdenum fine veins with a thickness of less than 6.5 mm and has a fine particle size of 2 μm. 95~97% of the molybdenum ore currently mined is derived from such fine veins; a small amount of molybdenite is present in the quartz-filled plate structure, impregnated with pegmatite lentils; inclusions in immersed rocks, and An irregular agglomerate that crystallizes in a high-silica rock.
Pyrite is the most abundant mineral in the Claymax mine, and it is usually found in quartz-pyrite-sericite veins containing topaz and fluorite .
Chalcopyrite, galena, bismuth needle sulfur galena (PbBiCuS 3) and sphalerite, a small amount of other sulphide Clay Max.
The tungsten is irregularly dispersed in the above fine veins, and is extremely fine particles of tungsten manganese ore. Moreover, fine veins containing tungsten-manganese ore occasionally intersect with quartz-formite fine veins.
Tin appears in the crystal hole in the tin or in the sericite deposit, sometimes in the fine veins of the quartz-pyrite-sericite. Typically, cassiterite is a loose cluster or plaque.
Titanium ore and ferrous rutile often enter tin or tungsten concentrates.
Mine mining is divided into two parts: mining and pit mining: the mining is in November 1973, the mining capacity is 30kt/d, using 15m 3 electric shovel, 120t truck to transport rock, 50t truck to transport ore. The extraction ratio of Lu Cai is 1.5:1. The pit mining is carried out by two 5600m flat roads in Stoke Lane, with a flat mining capacity of 30kt/d, using the nugget caving method. [next]
3, the crushing process
The traditional three-stage and one-closed process is broken.
The coarse and medium crushing are based on three mining points: two pits and one open pit are set separately. The coarse and medium-sized pieces of the middle section of 600m are set underground, and others are placed on the ground. After the ore is crushed to 38mm, it is sent to the plant for concentration and fine crushing. Finely crush the -38mm nugget to -13mm, or 72%-6.68mm. The process is shown in Figure 1.
Figure 1 Claymax crushing process
4, rough grinding - rough selection
(1) Process: a rough grinding, a rough selection, and two sweeps.
(2) Production index: ball mill grinding concentration 78%, steel ball unit consumption, 0.72kg/t, graded overflow fineness 60%~68%-100 mesh (or 40%~45%-200 mesh); raw ore grade 0.17% Mo; crude grade 3.6% ~ 4.8% Mo; crude selection of molybdenum recovery rate of 88%; daily processing of ore minerals 48kt; daily production of coarse concentrate ore 1800t.
(3) Equipment: ¢ 2.7 × 2.4m Marcy grid type ball mill 8 sets, power 340kW / set, speed 17r / min, production capacity 60 ~ 80t / h · Taiwan. ¢ 2.7 × 2.7m Marcy grid type ball mill 4 sets, power 450kW / set, speed 20r / min, production capacity 60 ~ 80t / h · Taiwan. ¢4.0×3.66m Alice-Chames and Maxi overflow ball mills total 8 sets, power 750kW/set, speed 14.5r/min, capacity 140~200t/h·set. The coarse grinding section has a total of 20 ball mills.
Rough selection equipment: 312 sets of Weining lm 3 flotation machine, 12 sets of Denver No24 Swb “A†flotation machine, and 10 sets of Akitel No48 flotation machine.
Sweeping equipment: 607 sets of Weining 1m 3 flotation machine, 24 sets of Denver No24 Swb “A†flotation machine, 22 sets of Agitair No48 flotation machine and 12 sets of Denver No300 flotation machine. A total of 999 sets of rough and sweeping.
(4) Pharmacy system: pine oil 18g / t (ball mill feed); steam oil (VaPoiooil) 318t / d (75% ball mill 25% sweep); Syntex (Syntex) 27g / t (ibid); Lime 336g/t (ball mill feed); water glass 227g/t (ball mill feed); Knox 14g/t (ball mill feed). [next]
5, selected sections
(1) Process: The coarse concentrate is concentrated and decontaminated, re-grinded by a three-stage gravel mill, scrubbed once, and selected five times; one or two selected ones each with a fine sweep. Fine cleaning can be thrown. See Figure 2.
Figure 2 Claymax flotation process
(2) Equipment: 4 sets of concentrated 脱 ¢ 610mm hydrocyclones and 2 sets of ¢ 30m concentrators. A section of 2×6.lm Marcy lattice type gravel mill, 150kW/set, 25r/min; ¢2.4×6.lm Maxi grid type gravel mill, 150kW/set, 22r/min. With D15B Krebs cyclone 8 sets of classification. One selection of 1m 3 Weining flotation machine 4 sets. Finely selected lm 3 Weining flotation machine 24 sets. In the second stage, two sets of 2.4×6.lm Marcy lattice type gravel mills were used, and eight D10B Krebs cyclones were used. The second selection of lm 3 Weining flotation machine 9 sets, sweeping 48 units. The three sections were refurbished with 2 sets of 2.4×6.lm Marcy lattice gravel grinders, and 6 sets of D10B Crex cyclones. Eight selected 1m 3 Weining flotation machines were selected three times. Four selected lm 3 Weining flotation machines for four times. Five selected 1m 3 Weining flotation machines were selected five times.
Concentrate treatment: 2 sets of ¢7.3m thickener, 2 sets of 1.8m Emco vane filter and 1 set of Holi-Flite steam spiral dryer. Pharmacy system: steam oil 409g / t, added to the flotation tank; sodium cyanide 222.5g / t, added to the gravel mill; Knox 4098 / t, added to the gravel mill; road -250.14g / t, plus Flotation tank; Naco 2.7g / t, added to the thickener. [next]
6, comprehensive recycling
Recovery of copper oxide, tungsten concentrate, sulfur concentrate and cassiterite from flotation tailings.
The mine recovered molybdenum oxide from tailings from 1960 to 1968: after coarsening tailings were enriched by cyclone, the molybdenum grade was increased from 0.012% to 0.014% to 0.25% to 0.35%, and leached with sulfurous acid. , activated carbon adsorption, ammonia washing, obtained ammonium molybdate crystal. After calcination, the product containing MoO 3 with a high purity of 99.98% was discontinued due to the high cost.
Claymax has been using a heavy-floating-magnetic combined process to recover tungsten concentrates, sulfur concentrates, cassiterites and monazite from rough tailings (Figure 3).
Figure 3 Comprehensive recovery of Sn, W, S, monazite process
7. Main products and output
Molybdenum concentrate 53%~56%Mo, yield 26kt/a (Mo); tin concentrate 49.9t/a (Sn); tungsten concentrate 733t/a (WO 3 ); sulfur concentrate 35.6kt/a; monazite 26.6t/a.
Molybdenum concentrate quality:
element | MoS2 | Mo | FeS2 | Pb (before dipping) | Pb (after immersion) | Cu | CaO | Acid not Soluble |
content (%) | 90 | 54 | 0.8 | 0.2 | 0.03 | 0.05 | 0.05 | 6 |
8. Transportation rate of main equipment (%)
The main equipment | Operating rate | Waiting | service | Blockage | ACCIDENT |
Rotary crusher | 48.9 | 32.2 | 4.6 | 13.4 | |
Jaw Crusher | 52.8 | 19.9 | 1.6 | 9.6 | 5.9 |
Standard crusher | 81.8 | 8.2 | 5 | 5.0 | |
Short head crusher | 86.5 | 4 | 4.5 | 2.0 | |
Rough grinding ball mill | 96 | 2 | 1.5 | 0.5 |
9, characteristics
(1) Claymax pioneered the roughing-roughing, multi-stage re-grinding-selection process. (2) The combination of steam oil and Xintex, the combination of Knox and sodium cyanide, pioneered molybdenum beneficiation . (3) Comprehensive utilization, tungsten, tin and pyrite, monazite with very low content can also be recycled. Smelting and recycling rhenium from the dust. (4) The ore dressing index is good, the molybdenum concentrate has high quality, high efficiency and low impurity. (5) The research work is in-depth, leading from mine development to applied research. (6) The level of automation is very high.
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