United States

Ray Mine

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Categories

Overview

Mine TypeOpen Pit
Commodities
  • Copper
Mining Method
  • Truck & Shovel / Loader
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ShapshotASARCO's Ray Complex is an integrated copper mining, milling and smelting operation. The Ray Complex encompasses the Ray Mine and SXEW Plant, the Ray and Hayden Concentrators, the Hayden Smelter and the Copper Basin Railroad.

The Hayden concentrator is located next to the Hayden smelter about 30 km from the Ray mine, and in 2023 it started operations for slag concentrates.

Owners

SourceSource
CompanyInterestOwnership
ASARCO LLC. (operator) 100 % Direct
Grupo Mexico, S.A.B. de C.V. 100 % Indirect
The Mining Division of Grupo Mexico, S.A. de C.V. (GMéxico) is controlled by Americas Mining Corporation (AMC) which operates the United States subsidiary - Asarco LLC (Asarco).

Asarco LLC includes the Mission, Ray and Silver Bell Arizona mines.

Deposit type

  • Porphyry

Summary:

The Ray Mine is located in eastern Pinal County, Arizona, about 80 miles southeast of the city of Phoenix. Ray consists of a large classical porphyry copper deposit.

The Ray sulfide system is developed in a variety of Precambrian rocks and Laramide intrusives. The bulk of the hypogene sulfides pyrite, chalcopyrite and molybdenite— occur in schist, the Ruin Granite (a quartz monzonite), quartzite and diabase, all Precambrian in age. Diabase is the youngest Precambrian rock and occurs as dikes and sills in all the older “country” rocks; it is the most receptive rock to copper mineralization and hosts the bulk of the ore at Ray. A series of Laramide (late Cretaceous) intermediate to acidic composition dikes and stocks, representing at least 12 different rock types, intruded all the older rocks. All Laramide rock types have been affected by the later Ray hypogene sulfide system and are cut by sulfide veinlets. Post-mineral Oligocene, Miocene and later volcanic and clastic rocks unconformably overlie part of the sulfide body. Major high-angle, northwest-trending normal faults extend through the deposit area, intersected by major northeast trending faults at the north end of the deposit with major deformation occurring before, after and perhaps during intrusion of ore-age dikes and stocks.

Hypogene mineral zoning is concentric, with a central low-grade core characterized by low total sulfides and a high cpy/py ratio. A higher grade zone (the “ore zone”) surrounds the low-grade core and is characterized by higher total sulfides but with a lower cpy/py ratio than the core. The increase in total sulfides continues regularly outward from the low-grade core but with a decreasing cpy/py ratio resulting in an outer high-sulfide, low copper, pyrite halo. Importantly, the center of this zonal pattern does not coincide with that of any of the porphyry stocks. Neither the deposit nor the intense depositassociated alteration coincides with the densest dike swarms and largest plutons of ore age exposed near the economic mineralization. Based on K-Ar dating from hydrothermal and igneous biotites, the alteration halos were developed at the same time as the Granite Mountain Porphyry which outcrops 4 miles S70°W from the orebody. Systematic changes of sulfide content and copper grade are related to rock type changes (quartzose Precambrian rocks, diabase, and Laramide porphyry) in the Ray orebody.

Ray consists of a large deposit of classical porphyry copper. Ray's geology is complicated by fault variation in the host rock, at least two dip incidents, a complicated enrichment history, hypogenic and supergenic alteration, and the removal of a significant part of the original mineralized shell. Mineralization is controlled by rock type, its position within the deposit, faults and its enrichment history. Most of the production has been of sulphide ore, full of chalcopyrite and chalcocite, undergoing recovery by concentration and smelting.

The pinal schist is a quartz-sericite schist found within the deposit zone and is the oldest unit found at the mine. The intrusive ruinous granite as batholiths in the Pinal Schist is a coarse-grained quartz monzonite that has been dated to 1.42 billion years old. After a long period of erosion and peniplanation, the youngest Precambrian quartz units of the Apache Group were deposited. The Apache Group units encountered at the mine are of the Pionera formation with the Scanlan basal conglomerate member and Dripping Spring quartzite with the Barnes basal conglomerate member. The Mescal limestone and basaltic units of the Apache Group are adjacent to the mining area, but do not show extensive mineralization. Extensive Dolorite intrusions, mostly sill-like, were embedded in the earlier units about 1.14 billion years ago.

The quartz-rich Pinal schist and Grupo Apache units are generally not good hosts for primary mineralization. Dolorite reacted with hypogenic mineralizing solutions and copper grades often exceed 1 percent. Most primary grade copper occurs in dolorite as chalcopyrite. In the areas close to the mine all the Paleozoic units have disappeared by erosion. Cretaceous intrusions are the next youngest units found in the mining area. Tortilla quartz diorite, dated to approximately 70 million years old, occurs mostly to the south and west of the deposit. The Granite Mountain porphyry, dated to approximately 61 million years ago, has long been considered to be the causative intrusion (origin of mineralizing solutions and copper) at Ray and occurs as a series of pockets of about 6.5 kilometers long and up to 3.2 kilometers wide. In the mining area, the Granite Mountain porphyry pockets are generally small and isolated. Teapot Mountain quartz monzonite porphyry invades as domes and dikes along a northeast trend north of Ray. Tertiary sedimentation began with a deposition of the Whitetail Conglomerate more than 32 million years ago. There is a significant basin of the Whitetail conglomerate to the west of the deposit. The Apache Leap rhyodacite tuff is 80 meters thick on the north side of the mine. The thickness increases to 488 meters near Superior, 17 kilometers to the north and is 20 million years old. The youngest Tertiary rock unit at Ray is a water-deposited rhyodacite tuff. That pinkish-brown tuff appears to interdigitate with Big Dome and appears on the map as the same unit. Rocks with similar ages to the west have been dated to be 14 to 16 million years old.

Secondary sulfide enrichment has a typical overlay shape. Most of the secondary enrichment is in the high sulfide zone in the pinal shale. A significant deposit of silicate mineral has been generated and it occurs as silicates, oxides, carbonates and native copper.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

CommodityProductUnits202320222021202020192018201720162015
Copper Cathode kt  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe1618152128
Copper Metal in concentrate kt  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe3437384647
Copper Concentrate kt  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe128153147172179

Operational metrics

Metrics202320222021202020192018201720162015
Daily milling capacity  ....  Subscribe  ....  Subscribe  ....  Subscribe
Stripping / waste ratio  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe0.61 0.51 0.31
Ore tonnes mined  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe25,512 kt29,358 kt24,369 kt21,720 kt30,482 kt
Total tonnes mined  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe40,971 kt44,422 kt31,867 kt29,673 kt51,316 kt
Tonnes milled  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe10,957 kt of ore (in concentrator)11,963 kt of ore (in concentrator)12,956 kt of ore (in concentrator)

Production Costs

Commodity production costs have not been reported.

Heavy Mobile Equipment

Fleet data has not been reported.

Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required May 29, 2024
....................... Subscription required ....................... Subscription required Subscription required May 29, 2024
....................... Subscription required ....................... Subscription required Subscription required May 29, 2024

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Aerial view:

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