TENIENTE MINE QUESTIONS

AND

ANSWERS

EL TENIENTE

MINE

BRADEN COPPER COMPANY GENERAL

WHEN WAS EL TENIENTE MINE FIRST DISCOVERED? It has been impossible to determine the exact date. Vestiges of implements íound there indícate the ipossibility that the Indians worked the mine aíter a fashion in the remóte past. In any case, in 1760 muleteers brought the practically hand-picked ore down on mulé back.

WHAT IS THE ORIGIN OF THE MINE’S ÑAME?

There are two versions. According to one of them a Spanish army lieutenant fleeing from justice escaped into the Andes and discovered the deposit, which thus became known by his military rank. The other equally well-known versión is that don Juan de Dios Correa y Saa, who endeavored to work the mine during half a century or more, had once served as a lieutenant in the Army of Liberation. As can be seen, in both versions the rank of lieutenant has been given as the origin of the ñame by which the mine later became known.

— 3 VVHO VVAS VVILLIAM BRADEN? An American engineer. He visited Chile at the end of last century as a machi­ néis salesman. A friend of his, Marco Chiapponi, later interested him in El Te­ niente Mine, which no local or European capitalist wanted to finance. Braden re- turned to Chile and carried out the ne- cessary preliminary explorations. Once he had raised the required initial capital, development commenced in 1904. This was the beginning of the Company which today proudly bears the ñame of this noted pioneer of Chilean mining.

SINCE WHEN HAS BRADEN BEEN A SUBSIDIARY OF KENNECOTT COPPER CORPORATION?

Since 1916. During 1960, Braden pro- duced almost 33% of Kennecott Copper Corporation’s total production. Kennecott is the world’s largest copper producer, with approximately 40% of total pro­ duction.

WHY DOES THE COPPER PRICE VARY? There are many copper producers, and stiff competition for sales. Copper is of- fered in open markets, where prices are neither regulated ñor artificially fixed. It is subject to the law of supply and demand. Henee the fluctuation in price.

IN WHAT ZONES DOES BRADEN OPERATE?

Mining activities are restricted to “El Teniente” Mine in Sewell. Braden pos- sesses other Camps, to which we will re-

4 — fer later, as well as offices in Rancagua, Santiago, Valparaiso, and San Antonio and lumber farms in the Provinces of Temueo and Cautín.

YVHY DOES BBADEN REQUISE LUMBER? For props in the tunnels of the mine and for construction purposes. Eucalyp- tus logs also are used in the copper re- fining process, as we will explain later. In all, 10,000 feet are used daily.

DOES BRADEN OWN EL TENIENTE MINE OR IS IT MERELY A CONCESSION? Braden bought the mine and the sur- rounding territory from the former own- ers, and the deposit belongs to Braden.

WHICH ARE THE COMPANY’S PRINCIPAL CAMPS? Sewell, Caletones and Coya. Apart from these there are smaller camps such as Pangal, Barahona, Parrón, etc.

SEWELL

7,000 feet above sea level and 46 miles by railroad from Rancagua. Nearly 3,000 persons work for Braden Copper Com- pany in Sewell, and the total population is approximately 12,000 persons.

— 5 This is where the mine, the mili, the Medical Department and Hospital, the Chemical Department, the Department oí Industrial Safety and Hygiene and the Construction and Maintenance Depart­ ment are situated. The town was named Sewell in honor of Mr. Barton Sewell, one oí the most enthusiastic workers in the large-scale de- velopment of the mine, and the first pre- sident of Braden Copper Company.

THE CAMP

DOES THE COMPANY CHARGE RENT OR IS HOUSING PRO VIDEO GRATIS? Hourly-paid workers pay no rent at all. The Company provides lodging for them and their families. Monthly-paid employ- ees pay a nominal rent.

WHAT ARE THE OTHER FRINGE BENEFITS GRANTED TO CAMP PERSONNEL? Hourly-paid workers receive free wa­ ter, electric light, and medical attention, including hospital and medicines. Mon­ thly-paid employees receive free water and electric ligflit and pay a nominal sum for the other Services. HOW IS ORDER MAINTAINED IN THE CAMPS? There is a detachment of the Chilean Carabineer Corps in the camps, and a law court in Sewell. They handle all matters to do with law and order.

6 — ABE THEBE ANY MUNICIPAL SERVICES?

No. The Company looks after Services normally considered municipal, such as gardens, Street lighting and cleaning, etc.

ABE THEBE ANY BELIGIOUS FACILITIES? Naturally. Catholic Services are held in all the camps and there is a churcíh in Sewell. Religious Services oí other deno- minations are also held. There is comple­ te religious íreedom.

WHAT FACILITIES DOES THE COMPANY GIVE FOB TRAVELLING ON HOLIDAYS? On Saturdays and Sundays there are special trains and additional railcars bet- ween the camps and Rancagua.

WHAT SCHOOLING FACILITIES ABE THEBE ON THE CAMPS FOB CHILDBEN?

In addition to the 10 State schools and one industrial sahool in the camps, the Company has 9 prívate schools. The Com­ pany also gives scholarships and main- tains a sohooling aid program for the ex­ clusive benefit oí the children of its employee and worker personnel, which assists them through secondary sehool and university. Another scholarship pro­ gram is carried out in conjunction with Kennecott Copper Corporation, oí which Braden is a sudsidiary, for university stu- dies in Chile, and the United States, and high-sahool studies in the United States.

— 7 VVHAT SPORTS FACILITIES ARE THERE? The Company always has been espe- cially concerned with providing the inha- bitants of its camps with necessary sports íacilities. For example, it has built swim- ming-pools, football fields, basketiball courts, golf courses, etc. and the Bra- den Stadium in Rancagua. It also spon- sors the national radio program “Braden Sports Network” and a local sportscast from Rancagua radio stations.

VVHAT DOES THE COMPANY DO FOR THE INIJABITANTS IN THE CULTURAL LINE? Apart from educational movie pro- grams, the Company contraéis the Ser­ vices of artists, lecturers, theater groups, etc. for all the camps and for Sewell. Fur- thermore, it sponsors several radio pro- grams, such as “Mid-day Magazine”, with national, foreign and camp news, as well as the transmission of concerts. There is also a Public Library in Sewell.

THE MINE

WHAT ARE THE CHIEF CHARACTERISTICS OF THE MINE? It is the largest underground copper mine in the world, with approximately 280 miles of tunnels. It makes use of gra- vity to extract the ore; that is to say, ore from the upper galleries falls to the low-

8 — er levels, from whence it is removed by railroad. There are two elevators in the interior of the mine, one of 1476 feet and the other of 1663 feet. The eompressor ehamber, situated in the heart of the mi­ ne, supplies the compressed air required for the work, and ventilating fans feed 300,000 cubic feet of air per minute through the galleries.

AT WHAT HEIGHT ABOVE SEA LEVEL ABE THE DIFFEBENT LEVELS SITUATED? The lowest level, where the railroad cars are loaded with ore from the mine, is 7,489 feet above sea level and the hig- hest 9,152 feet, or a difference of 1,663 feet.

HOW MANY PEOPLE WORK IN THE MINE? Roughly 1,500 between employees and workers. Naturally this figure ineludes the railroad personnel that work in the mine, underground warehouse personnel, supervisors, etc.

HOW MANY TONS OF OBE ABE EXTBACTED DAILY? In normal times some 35,000 tons of ore are extracted daily, with a cop- per contení of approximately 2%, whieh means that the Mine Railroad transports over 11,000,000 tons a year. This railroad possesses 12 electric locomotives and eigh- ty 25 ton cars for the transportation of ore, plus other cars for the transporta­ tion of materials.

— 9 CAN THE PRODUCTION OF THE MINE BE INCREASED? Important programs for the expansión and modernization of installations to in­ crease production are at present being studied. But in the present site, installed capacity cannot be increased beyond 25%, due to limitations of the water supply re- quired to treat the ore.

IS WATER VERY IMPORTANT? Yes. For instance, in order to treat 30,000 tons of ore a day (normally 35,000 tons are extracted), 26,400,000 gallons of water are required by the Mili alone. As we have already said, production depends entirely upon the water supply. In order to produce 56,000 KW. of electric power 9,240,000 gallons of water are required per minute.

WHAT AMOUNT OF EXPLOSIVES ARE USED DAILY IN THE MINE? Approximately 0.08 pounds per ton of dry ore or considerably more than one ton a day. In addition, approximately 1,400 detonators and roughly 10,000 feet of wick are used daily.

THE MILL

WHAT DOES THE MILL DO? The ore, whioh arrives at the Mili in rock form, goes through a double dry- crushing process. It is then mixed' with

10 — water and reagents and conveyed to the ball milis. Sulphuric acid and ílotation reagents are added and the minute parti- cles ol copper sulphide in the ore are then recovered by ílotation. Thereafter water and reagents are filtered oíf and the re- maining copper concéntrate containing approximately 33% copper is sent by aerial tramway to the Caletones smelter.

HOW MUCH SULPHURIC ACID IS USED IN THE OPERATION?

4.5 pounds are used per ton ol ore pro- cessed, which gives a total varying around 80 tons a day.

HOW IS THE ACID OBTAINED?

It comes írom the sulphuric acid plant in Caletones, as will be explained later.

IS THE SMELL OF THE CONCENTRATE HARMFUL TO THE LUNGS? No. This has been proved in repeated medical tests.

HOW MANY PEOPLE WORK IN THE MILL?

Almost 600, between employees and workers.

— 11 HOW MANY TONS OF CONCENTRATES REA VE THE MIRE DAIRY?

If 30,000 tons of ore are received daily, approximately 1,500 tons ol concéntrales are produced.

WHAT IS THE COPPER CONTENT OF THE CONCENTRATES IN THE DIFFERENT STAGES OF THE PROCESS?

Primary flotation concéntrate - 20%; copper-sand concéntrate ■ 25%; slime tail - 30%; general mili concéntrate - 33%.

INDUSTRIAL SAFETY AND HYGIENE DEPARTMENT

WHAT IS THE PURPOSE OF THIS DEPARTMENT?

It is responsible for the prevention of accidents and maintenance of the best pos- sible working conditions, as indicated by the ñame of Industrial Safety and Hygi- ene Department. The constant activity of this department has made Braden Copper Company one of the safest mining com- panies on the continent. For the past 13 consecutive years Braden has received the Inter-American Safety Prize, an un- matched record.

12 — HOW ABE WORKERS PROTECTED?

First, with helmets, protective shoes and special masks. Secondly, by all the latest safety measures, such as: wet dril- ling to lay the dust; constant measure- ment of the dust in suspensión; torced air ventilation in all the galleries; special doors to isolate any threatened sector; alarm systems operating with light and sound signáis, injection of gases with a penetrating odor, etc. Workers are con- stantly trained in the use of implements, and periodically attend refresher courses to develop their concepts of industrial safety.

ABE ACCIDENTS FBEQUENT IN THE DIFFEBENT TASKS?

The highest figure corresponds to the mine, whioh is only 12 accidents per mil- lion manhours. The Electrical Dept. has the lowest figure. The average for the whole plant is 4.7 accidents per million manhours worked, one o>f the lowest in the world for underground mining opera- tions.

WHAT IS THE PRINCIPAL CAUSE OF ACCIDENTS?

In the mine, the greater percentage is caused through falling rocks. Monthly analyses of accidents are prepared to de­ termine precisely the cause and to adopt the necessary measures to avoid a repe- tition.

— 13 WHY IS GREATER IMPORTANCE ATTACIIED TO ACCIDENT FREQUENCY THAN TO THE SERIOUSNESS OF SAME?

Frequeney is accepted throughout the world as the best way to estimate the success oí a company’s safety measures. Furthermore, one usually íinds that a company with low accident frequeney al- so has a low rate oí serious accidents.

IS THERE A FIRE BRIGADE IN SEWELL AND THE OTHER DEPARTMENTS?

Yes. It also has the latest equipment. It is organized on a volunteer and paid basis and Is drilled periodically. The In­ dustrial Safety and Hygiene Department also has specially trained personnel, and special modera apparatus for rescue work.

.1 co. THE HOSPITAL

IS THE HOSPITAL MAINTAINED BY THE COMPANY ESPECIALLY FOR ITS PERSONNEL?

Yes. Its equipment and apparatus are amonig the most modera in Chile. In addi- tion to the treatment oí illnesses, both serious and simple, and the necessary sur- gical treatment, an average of 600 babies are born here each year. The hospital has the lowest infant mortality in the coun-

14 — try. Mothers are given special pre-and post-natal care. All children oí employees receive free medical care up to 18 years oí age.

HOW MANY PEOPI.E WORK IN THE MEDICAL DEPARTMENT? Approximately 160 persons, including 22 doctors.

CALETONES

Is situated 5,100 íeet above sea level and 34 miles from Rancagua. It has a population oí nearly 3,000 inhabitants. Approximately 1,100 persons, between em­ ployees and workers are stationed in this camp. The Smelter and sulphuric acid plant are here. The principal land-mark in the Caletones area is the smelter’s im- mense ehimney, which is 250 íeet high and 60 íeet diameter at its base.

z co\ ' ‘ THE SMELTER

WHAT IS THE OBJECT OF BURNING EUCALYPTUS LOGS IN THE FURNACE? To remove the oxygen from the copper oxide which may have formed in the lur- nace during the oxidation oí other impu- rities.

— 15 SINCE WHEN HAS THE BESSEMEB CONVERTER, DESIGNED TO CONVERT IKON INTO STEEL, BEEN USED FOR COPPER?

An acid-lined Bessemer converter was first used for copper by Pierre Manhes in France in 1880, but this was not very satisíactory. The first basic-lined convert­ er was used in Utah, U.S.A., in 1910. The horizontal Pierce-Smith converter, used by Braden Copper Company, is now the most common.

VVIIAT IS THE DIFFERENCE BETWEEN COPPER MATTE, BLISTER AND REFENED COPPER?

Copper matte contains approximately 50% copper, and is produced by heating the roasted concentrates in the reverbe- ratory fumaces. The second process, whioh consists of blowing the liquid me­ tal with compressed air in the converters, eliminates most of the sulphur content in the form of sulphur dioxide, and produ­ ces “blister” or “Bessemer” copper, with a copper content of 99.43%. Part of the copper is sold in this form, and part con­ tinúes to the refining furnaces where by means of two processes — oxidation and reduction — 99.92% puré fire-refined copper is obtained.

WHAT ARE THE INDUSTRIAL USES FOR THE DIFFERENT TYPES OF COPPER PRODUCED BY BRADEN?

A considerable amount of blister is used in the manufacture of copper sul- phate for agricultural purposes; it is also refined electrolytically for electrical uses.

16 — Fire-refined copper, either in this form or in alloys, has a wide variety of uses, such as castings, sheets, pipes, etc., and as a matter of fact it can be used for prac- tically anything except electric wire and equipment.

HOW MANY PEOPLE WORK AT THE SMELTER? The number varíes between 650 and 750.

HOW MANY TONS OF COPPER ARE PRODUCED DAILY BY THE SMELTER? An average of 500 tons daily.

« O THE SULPHURIC ACID PLANT

HOW IS SULPHURIC ACID PRODUCED? By using the sulphur dioxide in the ga­ ses in the converters. The gases are first washed and then dried. They are then heated in the Contact Plant and the sul­ phur dioxide is converted into sulphuric aríhidride in the presence of a catalyst. When cool, water is added to the sulphu­ ric anhydride to produce sulphuric acid.

HOW MUCH SULPHURIC ACID IS PRODUCED DAILY? The plant can produce up to 100 tons of acid daily.

— 17 COYA AND PANGAL

Between Coya and Pangal there are some 350 persons employed by the Com- pany, and the total population of the two camps is about 1,200. Coya is approxi- mately 19 miles from Rancagua and 2,500 feet above sea level. Pangal is 7% miles further up than Coya. The company’s principal hydroelectric plants are in these two locations. The ohildren’s summer camp for the mine is located in Coya, a fertile valley surrounded by beautiíul scenery whidh makes it one of the love- liest spots in Chile.

WHAT IS THE HEIGHT OF THE PENSTOCKS? In Pangal, 1,600 feet; in Coya, 439 feet.

WHAT IS THE PRESSURE IN THE TURBINE CASES? In Pangal, the static pressure is 680 pounds per square inch, and in Coya, 178 pounds per square inch.

WHAT PBOTECTION IS THERE AGAINST ELECTRIC AND HYDRAULIC FAILURES? Lightning conductors on the transmis- sion lines; overload relays in the circuits; parallel transmission circuits protected by relays which deviate the charge to the unaffected Circuit. Against hydraulic de- fects there are pressure gauges and gau-

18 — ges to measure the water in the canals, with visual indicators on the operator’s panel. The operator is in telephone com- munieation with all the intakes and gates in the canal. He can also opérate the pen- stock valves by remóte control, entirely cutting oíf the water in case oí penstock lailure.

WHAT IS THE VOLTAGE OF THE TRANSMISSION LINES? Pangal-Coya and Coya-Caletones-Sewell, 69,000 volts; Coya-Rancagua, 34,500 volts.

WHAT IS THE LENGTH OF THE TRANSMISSION LINES? Pangal-Coya, 5% miles. Coya-Sewell, 14 miles. Coya-Rancagua, 19 miles.

HOW MUCH POWER DO THE HYDROELECTRIC PLANTS AT COYA AND PANGAL GENERATE? The installed capacity in Coya is 30,500 KW. and in Pangal, 24,000 KW. Currently over 397,000,000 kilowatt-hours are gene- rated per year.

FOR WHAT IS ALL THIS ELECTRIC POWER USED? To move all the Company’s maohinery. For instance, the mine alone uses 1.40 KWH per dry ton oí ore produced, which at today’s average rate oí production re- presents some 490,000 KWH a day. It is also used for the domestic and municipal requirements oí the camps and the Bra- den premises in Rancagua. In the Mili, over 2,000 electric motors, some oí 400 HP, consume 630,000 KWH daily.

— 19 SAPOS, BARAHONA AND PARRON

These are three of the Company’s small camps. Sapos is located just below Sewell. Here the tailings are precipitated in order to recover the water, 20% of which is pumped back to the Mili to be used again in the industrial process. The tailings are then earried along 37 miles of flume line to Parrón, where the dispo- sal dam is located. This line involved building 18 Steel and 330 wooden bridges; the highest of which is 249 feet and the longest 1,135 feet.

z co\ RANCAGUA

This is where Braden’s administrative offices, yards and shops are. The other departments which have headquarters here are the Comptroller’s, Industrial Re- lations and Railroad Departments. Ap- proximately 1,700 persons work for Bra- den in Rancagua. The copper is loaded here on to the State Railways which car- ry it to San Antonio, from where it is exported to foreign markets. The work- shops supply the spare parts and new equipment required for the plant which can be made locally and also have an elec- tric fumace for alloying their own spe- cial steels.

20 t CO* * o » VALPARAISO AND SAN ANTONIO

WHAT ACTIVITIES ARE CARRIED OUT IN THESE PORTS? The offices in these ports are in charge oí Port Agents. Most oí the imported pro­ ducís required for the company’s opera- tions are shipped to Valparaíso, the larg- er oí the two ports. The copper is ship­ ped from San Antonio, where a certain amount of material is also disembarked.

TO WHAT COUNTRIES IS «EL TENIENTE” COPPER EXPORTED? Principally to England, Italy, Spain, Germany, United States, France and Swit- zerland.

THE RAILROAD

WHEN WAS THE RANCAGUA TO SEWELL RAILROAD BUILT? Construction commenced in 1906 and was completed in 1911. Even today it is considered a remarkable feat of engineer- ing. The narrow gauge railway line (30 inches) between Rancagua and Sewell co- vers approximately 46 miles.

— 21 HOW DID ONE GET TO SEWEEL BEFORE THE RAILROAD WAS CONSTRUCTED?

The Company built an ox-cart road írom Graneros to Sewell. At one time there were as many as 250 carts on the road. Until 1911 all the equipment, ma- ehinery and materials were transported in this way.

S C°V STATISTICS AND SUNDRY

HOW MANY PEOPLE WORK FOR THE COMPANY?

Roughly 7,000 persons between employ- ees and workers.

ARE MANY OF THESE FOREIGNERS?

No. Aetually only 99 out ol the 7,000 are foreigners, or say, approximately 1.4%, and these are o

WHAT DID THE COMPANY PAY OUT IN SALARIES AND WAGES DURING 1960?

Approximately E° 23,700,000.

22 — WHAT DOES THE COPPER INDUSTRY MEAN TO NATIONAL ECONOMY?

In 1960 the large copper mining indus- try paid over 88 million dollars in taxes. Braden’s share oí this was over 51 mil­ lion dollars, or say 57.9% oí the amount received by the State from the Large Copper Mining Industry. Furthermore, Braden returned to the country over 28 million dollars to cover production costs.

WHAT DOES THE COMPANY SPEND ON PERCHASES IN CHILE?

In 1960 Braden Copper Company spent more than 5,900,000 escudos on local pur- chases, that is to say, over 16,000 escu­ dos daily.

DOES ONE REQUERE SPECIAL CLOTHING TO ENTER THE MINE AND THE MILL?

It is advisable to use oíd clothes. The Company provides visitors with special clothinig to enter the mine but not the mili. During the Processing of the ore in the mili a by-product, known as mo- lybdenite, is obtained in the form oí a dark powder, which sticks to clothes. Al- so, the concentrates may cause stains dur­ ing some stages of concentraron. Be- cause of this we suggest that oíd clothes be wom for visits.

— 23