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its entire eet and chose Atlas Copco tobe its sole supplier, not only for drillingequipment which was already widelyused, but for loading and haulage equip-ment as well.

The benet of this move to standard-ization is that it makes things easier whenit comes to parts and training personnel,says Javier Flores Melndez, ProaosStrategy Manager. Atlas Copco also hasgood technical personnel for service andthis is very important for us.

The Atlas Copco distribution and ser-vice centre is also a key factor. Strategi-cally placed in nearby Caleras, it wasoriginally set up to support the localmining community but now also servesother mines around the country.

Flores Melndez continues: We have

clearly beneted from the existence andcloseness of this centre. Our relationshipwith Atlas Copco has been good formany years, but the centre has helped tostrengthen it because it shows their com-mitment to our operations.

Mechanization, Flores Melndez ex-plains, has been crucial in helping themine consolidate its leading position inthe world market for silver-lead concen-trates. We started mechanizing our op-erations about 40 years ago and duringthe last 30 years there has been a steadyincrease in production. This has put us ina privileged position when it comes tosilver production, he says. He adds thatthe production target has now been

Mechanization and service combine to support two of the countrysUNDERGROUND INMM

exican mines Proao and Fran-cisco I. Madero, in the state of Zacatecas, are no ordinary un-

derground operations. The former is theworlds largest and most protable un-derground silver mine and the latter isthe countrys largest underground zinc

mine. Their operations differ in every as-pect except one. They both use state-of-the-art equipment and services fromthe same supplier, Atlas Copco.

Long-term commitmentProao, also known as Fresnillo due to itsclose proximity to Fresnillo City, is run byCompaia Fresnillo, SA de CV, a wholly-owned subsidiary of Peoles Group. Themines history dates back as far as the1550s, but there is nothing historic aboutthe methods employed today or the equip-ment which includes some of the most so-phisticated mining machinery available.

After working with several differentsuppliers, Proao decided to standardize

The servicecentre hasstrengthened our relations.

Javier Flores Melndez,Strategy Manager,Proao Mine.

Proao and Francisco I. Madero are twoof Mexicos most successful mines.Owned by the Industrias Peoles group,both use modern, mechanized equip-ment and rely on the same sup-plier to keep their eets upand running, and their costsdown. Adriana Potts reports on thearrangement and its contribution to themines overall performance.


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M INING &CONSTRUCTION

M E X I C O

GUATEMALA

BELIZE

HONDURAS

EL SALVADOR

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G U L F O F M E X I C O

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Mexico City

Madero Mine

Atlas Copco Mexicana(Tlalnepantla)

Proao Mine (Fresnillo)

Zacatecas

Atlas Copco Distribution& Service Cen t re(Caleras)

most important mines

In the Proao mine, production drilling is carried out with both upholes and down- holes. After working with tophammer rigs

such as this Simba 1254, the mine is gradually moving over to in-the-hole-

drilling and has invested in several Simba M4 C-ITH rigs.

raised once again from 1.6 to 2.5 mil-lion tonnes a year. This represents an in-crease of more than 60 percent.

The challenge of changeDuring its long history, the mine hasseen several changes in working meth-

ods, and each time, new technology andnew equipment has had to be introduced.For example, the mine has gone fromcut-and-ll to sub-level stoping and isnow gradually moving from tophammerdrilling to in-the-hole (ITH) drilling.

Ricardo Galindo Lozano, Manager of Mining Operations, says the mine hashad to adapt to varying geology and ore-body geometry as well as new demandsfor increased production and safety.

The previous method was cut andll with upwards drilling, he recalls.Now the amount of drilling and thehole diameter have changed and we usesub-level stoping with rell. (See illus-tration, p 14). Changes in the orebody

safety, productivity increases and yourcosts come down, he adds.Throughout the process of change,

Flores Melndez says Atlas Copco hasbeen a strategic ally: We have beenworking together for several years toadapt and innovate due to the changes themine has had to go through, not only withthe primary equipment but also with ser-vice, training, inventory management andparts stock.

During the rst three months of 2006,the entire Atlas Copco eet achieved anavailability of 89.5 percent and the objec-tive is to reach 90 percent. For this reason,the eet has been expanded with the addi-EXICO

Key players in Proaos process of change: Humberto Flores Molina of Atlas Copco Mexicana(left) with Ricardo Galindo Lozano, Manager, Mining Operations, with the Rocket Boomer 281.

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have allowed long-hole drilling to be ap-plied using Simba drill rigs. We wentthrough a fast learning curve with long-hole drilling, continues Galindo Lazono.

At rst, we used a competitors rig but itwas too manual and didnt have the ver-satility that the automated Atlas Copcoequipment has. With the Simba M4C-ITH, PC-controlled rig, we drill 25 to32 metres of 4.5-inch holes, upwards anddownwards. The machine is incredible; itdoes all this drilling in one set-up. Itsone of the best weve ever had here.

Galindo Lozano says that the methodprovides better safety and higher produc-tivity at lower cost. Productivity has beenincreased by about 30 percent, thanks tobetter accuracy and less deviation. Thecompany has safety at the top of its prior-ity list so this makes sense; if you have


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tion of three Rocket Boomer 281 rigs formine development (bringing the total toseven) and one Simba M4 C -ITHproduction drill rig (bringing thetotal to three, in addition to theeet of six Simba 1254s). Themine has also invested in ve newScooptram ST1030 loaders (bring-ing the total to 22) and twoMinetruck MT2000s (bringing thetotal to eight). A service agreementfor the Simba rigs has been intro-duced involving the presence of four Atlas Copco technicians onsite, and at the time of M&Cs vis-it, discussions were under way to intro-duce a similar arrangement for the loaders.

Recognizing Atlas Copcos long pres-ence in Mexico, Flores Melndez says:Ever since I started in this industry some

30 years ago, I remember seeing AtlasCopco equipment around. They startedwith pneumatic, then hydraulic and nowcomputerized equipment, so the equip-ment here at Proao is a good representa-tion of Atlas Copcos technological de-velopment.

The Proao eet also includes fourDiamec core drilling rigs, two Boltec rock bolters, 13 Rocket Boomer 104 drill rigs,and three Robbins raiseborers. Secorocdrill steel is also used on some of the de-velopment and production rigs. In early2008, the mine will take delivery of aRobbins 34RH raiseborer, specially de-signed for drilling 720 mm slotholes to adepth of 20-30 metres. The power of the

34RH combined with the unique down-reamer developed by Secoroc, allows forhigh penetration which will reduce the

cycle time for making slotholes.

A rst in explorationProaos approach to mechanization isalso evident when it comes to exploration.The mine has two Diamec U6 APC deephole drill rigs that were acquired in 2003,making it the rst mine in the Americas touse this type of equipment.

Geologist Jos Manuel Ambriz sayshole depths of between 300 and 600 me-tres are drilled using the smaller Diamec252 and 262 units while the Diamec U6units are used to drill deep and distant tar-gets. With the rst U6 unit, we drilled1,300 metres of horizontal, standard sizedholes and we only used one drill, which is

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amazing, he says. With the secondDiamec U6 we drilled 1,000 metres. Itwas an interesting learning process for usas well as Atlas Copco. We had no previ-ous experience with this technology butwere pleased with the machine. It givesgood productivity and has good penetra-tion speed. Working with it has becomeeasy, and using six-metre core barrels,productivity increased by 25 percent.

Totally modern MaderoBy comparison, the Francisco I. Madero

mine, named after former President of Mexico, Francisco Ignacio Madero, is ayoung mine and one of the newest in thePeoles Group. Located some 15 kmnorth of the city of Zacatecas, it wentinto commercial production in 2001.

Its main products are zinc and leadconcentrates and at the end of 2005 ithad reserves of 27.5 million tonnes withan average zinc grade of 3.3 percent and0.74 percent of lead.

An investment of USD 125.8 millionand a capacity of 8,000 tonnes per dayhas quickly made it Mexicos largest un-derground zinc producer. In 2005, it pro-duced 65,948 tonnes of zinc concentrateand 31,572 t during the rst half of 2006.

Left: The drilling possibilities of- fered by the Simba M4 C.1500

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Here, the vision was to create a trulymodern, 21st century mine. For exam-ple, it has a radio system for internal andexternal communication with voice, dataand video channels for person-to-personcommunication, production control, lo-cation of vehicles and safety procedures.Atlas Copco was involved in the devel-opment work at an early stage and has

subsequently provided technical supportfor planning and development.The rst order of equipment included

some of the latest Atlas Copco comput-erized products four Rocket BoomerL1 C and three Rocket Boomer L2 Celectro-hydraulic drill rigs with singleand twin booms respectively.

These rigs, which come with enclosed,air-conditioned cabs, feature ABC Regu-lar computerized rig control. To keep theeet up and running, the mine has an AtlasCopco service and maintenance contract.The largest of its kind in the country, thecontract comprising a team of around 20mechanics and supervisors supported bythe Atlas Copco distribution and servicecentre in nearby Caleras.

Productive and safeSergio Flores Gomez, General Managerat Madero says: The Atlas Copco equip-ment is productive and safe, and, general-ly speaking, it has contributed to therapid and safe advance in production at

this mine.Weve always had good relations but

when Atlas Copco set up the distributionand service centre in Caleras, just 20 kmfrom here, it was a key factor for us. Tohave this facility so close, and to havethe service and maintenance contract inplace, gives us peace of mind. We knowwe can carry on with our productionwork and if theres a problem and a ma-chine stops, the expertise and any partsthat might be needed are right there. Thismakes it a lot easier for us.

Developing the mineFor development and production, Maderoemploys several contractors, among them

Minera Castellana which carries out ex-ploration, development and about half theproduction work. Development work isalso carried out by Arconso and PaniaguaObras Mineras.

Olivero Tiger Paniagua, owner of Paniagua Obras Mineras, says a drill pat-tern of 60 holes is used for developmentwork and that his company has a contract

to drill at least 200 metres per month. Forthis, the company uses one of MaderosRocket Boomer L1 C rigs equipped withCOP 1838 rock drills as well as one of the Scooptram ST8C loaders for muck-ing out. At the time of M&Cs visit, thecompany had achieved 235 metres of de-velopment work in just one month.

Paniagua says: I have worked with

Inside Proao: The mine layout showingextraction via sub-level stoping. Besides

production drilling, mine development work amounting to some 36,000 metres per year (3,000 m/month) is also carried out.


Personal service at Proao: Left, Antonio Gonzalez, Mine Captain, San Carlos area, with (far right) Runo Molina, Atlas Copco Drill Master and Simba rig operators.

Strong commitmentfrom a good neighbour

OOver the years, expansion at theProao mine has brought its op-

erations almost within theboundaries of the nearby city of Fres-nillo. As a result, the mine has a broad-based commitment to the local envi-ronment. To limit the impact of itsoperation, the company invests in envi-ronmentally friendly equipment. It hasbeen awarded an ISO 14000 Environ-mental Management System certica-tion as well as a Clean Industry Regis-tration by the Mexican authorities. Ithas founded an ecological park in thearea as a sanctuary for various speciesof mammals, birds and reptiles, andhas also established a tourist mine aswell as a mining museum to familiar-

ize local people with the mining pro-cess and to preserve the history of the

industry. In 2004, the company openedParque los Jales, a public area that in-cludes lakes and open areas for recre-ation. This facility was built on the landformerly occupied by the tailings pond.Says Strategy Manager JavierFlores Melndez: We wishto be regarded not just as alocal company but also agood neighbour.

Preserving history: An artifact in the localmining musem, provided by Proao.

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much lower so we dont have to use asmuch support. This is an important fac-tor in an operation that needs roof sup-port in all areas (using a combination of shotcreting and rock bolting), and wheresome 40 percent of the open areas re-quire extra support.

In-mine maintenanceFor this work, two Boltec 235 rock bolt-ing rigs are used to install nine rock boltsper hour, or 56 rock bolts per shift.Sometimes it even does 70 bolts pershift, but this depends on the quality of the rock which varies and can be verypoor in some areas. On average, we in-stall about 3,000 bolts per month, saysJimenez, and tests have shown that theload capacity of the bolts is 17 tonnes,which we think is very good.

Most of the mined material is dis-charged by gravity to chutes on the 2020

level. From there it is then hauled in 40-tonne trucks on a horizontal circuit onthe main haulage level, 210 metres be-low the surface. Ore transport to the sur-face is via two conveyor belts.

Like Proao, Maderos service andmaintenance contract also covers opera-tor training. Jorge Alvarado, Head of Mining Maintenance, says: The servicecontract is good. We follow a specicprogramme every week depending on themachines to be serviced. About half of them have been working between 18,000and 20,000 hours without any rebuild thats a pretty good reference for thisequipment.


Atlas Copco equipment for at least 25years of the 30 years that I have been in themining business. The drill rig were usingis the oldest here in Madero. It arrivedabout six years ago and yet it is the onethat delivers the best results. We have agood relationship with Atlas Copco andparticularly with the mechanics who giveus good support with the service of themachines.

Rig operator Enrique Barajas hasbeen at Madero for three years with oneyear on the Rocket Boomer L1 C. Be-cause of the computerized controls this

machine is easy to work with, he says.I had no problems learning the comput-er system and I also like the space andcomfort in the cabin. Refugio Martinezhas been at Madero for ve years, threeof which as a Scooptram ST8C loaderoperator. He says: This is a good ma-chine. It is the most modern LHD I haveworked with and the controls are easy tomanoeuvre. I had no problem learninghow to operate it.

Poor groundDue to the generally poor ground condi-tions at Madero, the mine uses the cut-and-ll with room and pillar method. This

opens voids of 8-10 metres, bounded bynon-recoverable pillars of six metres insquare sections. Mineral recovery is closeto 90 percent.

Both horizontal and vertical drilling isemployed, but that may soon change. AsDavid Jimenez, Mining Supervisor, ex-plains: At present we do about 70 percenthorizontal drilling and 30 percent verticaldrilling, but were looking to change thatto 100 percent horizontal. We expect tomake the changeover by mid-2007.

One of the main reasons for thechange to horizontal drilling is roof sup-port. Continues Jimenez: With horizon-tal drilling, the roof doesnt suffer toomuch damage and the risk of rockfalls is M&C 1 07

THE CALERAS FACTORAtlas Copcos distribution and service centrein Mexico is strategically placed in Caleras, in the state of Zacatecas, right in the centre of the country.

The centre was originally established in2001 to support the nearby mining operationsof Proao and Francisco I. Madero with distri-bution of parts and equipment and rebuildsand repairs of large components.

Although both mines derive clear benetsfrom their close proximity to the centre, othermines in the country are now also beingserved from Caleras.

Humberto Flores Malina of Atlas CopcoMexicana says: As the distribution centre isright in the centre of Mexico, it is easy for our technicians to mobilize from here to the rest of the country.

The Rocket Boomer L2 C drill rig,equipped with COP 1838 rock drills,in the Madero mine.

The servicecontract givesus peace of mind.

Sergio Flores Gomez,General Manager,Madero Mine.

underground in mexico 1-07_11-13-2009 5-07-06 pm

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