“EXPERIENCES OF WASTEWATER AND WATER REUSE AT PEÑOLES INDUSTRIES: THE CASES OF MET – MEX AND

FRANCISCO I. MADERO”

• Peñoles was founded in 1887.

• Peñoles is a mining group with integrated operations in smelting and refining of non-ferrous metals, and producing inorganic chemicals.

• Peñoles is the world largest producer of refined silver, metallic bismuth and sodium sulfate, the leading Latin American producer of refined lead and zinc, and Mexico’s largest refined gold producer.

What is Peñoles?

MISSION

Shareholders

Cu

sto

mer

sP

erson

nel

Suppliers Community

Adding value in a sustainable

manner

To add value to non-renewable natural resources in a sustainable manner.

FCO. I. MADERO

MET - MEX

Met – Mex is a metallurgical complex located in Torreón, Coahuila and Francisco I. Madero Mining Unit is a Zinc

Concentrating Plant, near Zacatecas, City.

Reducing water extractions through an

efficient usage

Increasing water availability through

environmental infrastructure for

reuse and distribution

EXTRACTIONS NATURAL AVAILABILITY

PROPOSED HYDROLOGICAL BALANCE

• Customs, values, attitudes and habits a person or a

society has regarding water importance.

• Availability of water resources in the environment

and the required actions to get, distribute, clean and

reuse it.

• This culture implies compromise to appraise and

preserve it, using it with social and environmental

responsibility.

WHAT DOES WATER CULTURE MEAN?

WHY SHOULD WE TREAT RESIDUAL WATER?

• To help the balance between the Earth and the Hydrosphere. There is only a certain capacity to receive, absorb and transform different kinds of wastes into nutrients.

• If we exceed this carrying capacity, wastes will accumulate given origin to water contamination.

• When the extraction is greater than recharge, water will become scarce.

Availability zone pesos/ m3

Prices per cubic meter according to Availability Zones established on the Mexican Federal Law on Water Rights

(Article 223)

I 14.3343

IIII 14.63014.630

III 9.5557

IV 7.8837

V 6.2111

VI 5.6135

VII 4.2252

VIII 1.5012

IX 1.1250

• In Met-Mex Peñoles, Gold, Silver, Lead, Zinc and

Bismuth, are refined from ores and concentrates

and these processes consume water.

• The City of Torreon, Coahuila, belongs to

Availability Zone II, whose right to make use of

water is 14.63 Pesos / cubic meter.

• Water consumption at our facilities is:

12,000 m3 /day (139 LPS)

Well water

Raw Sewage from the city

Evaporation

Water in productsPROCESSES

GENERAL SCHEME FOR WATER MANAGEMENT AT MET - MEX

Residual Water

GENERALSERVICES

GREEN AREAS

TREATMENT PLANT

TREATMENTBattery Limit

EVAPORATION

REPLACING WATER

GREEN AREAS

WASTEWATER GENERATION, TREATMENT AND REUSE

PLANT AND OFFICE INTERNAL DRAINAGE

WASTE WATER TREATMENT

PLANTS

REVERSE OSMOSIS ZINC PLANT

BOILER FEED WATER PRODUCTION

NANO-FILTRATION

NEUTRALIZATION

PURGE

SEWAGE CITY WATER

COOLING TOWERS

SLAG GRANULATION

LEAD SMELTER AND REFINERY

LEAD ACID PLANT

ZINC ACID PLANT

EXTENDED AERATION REACTOR

AC

TIV

AT

OR

SL

UD

GE

DIG

ES

TE

R

RAW SEWAGEGARBAGE SCREEN SETTLING

TANK

ROTATING DRUM FILTER

SEDIMENTATION

TANK

ANTHRACITE AND CARBON FILTERS

UV DESINFECTION

WASTE WATER TREATMENT PROCESS

DIGESTED SLUDGE TO COMPOSTE

WATER TO PROCESSES AND

REVERSE OSMOSIS

PRESS FILTER

AIR

MULTISTAGE WASTEWATER TREATMENT PROCESS

AT MET - MEX

BOD 330 <5 0 0

TSS 40 15 0.5 0.3

TDS 1,300 1,300 80 5

pH 7.0 7.0 6.0 9.0

HARDNESS 400 400 10 <1.0

Ca +2 120 120 3 <1.0

PO4 20 15 2 0

Cl 120 110 15 <1.0

Mg 30 30 <1.0 <0.02

SiO2 30 30 5 <1.0

Conductivity 1,600 1,450 60 <0.25

μ mohos

WASTE WATER

TREATED WATER

AFTER REVERSE OSMOSIS

AFTER IONIC EXCHANGE

SUMMARY OF WATER CONSUMPTION AND SAVINGS AT MET-MEX PEÑOLES

TOTAL DAILY CONSUMPTION 12,000 m3

WATER RIGHTS 13,500 USD / day

COST OF TREATMENT 0.20 USD / m3

NOT USED WELL WATER 11,300 m3 /day

INVESTMENT FOR A 130 LPS PLANT = 4 MILLION USD

APPROXIMATE SAVINGS = 3.8 MILLION DOLLARS / YEAR

FRANCISCO I. MADERO MINEWASTE WATER TREATMENT FACILITIES

8 8

Digested Sludge to promote revegetation on tailings dam

Raw sewage from

Zacatecas City

Q = 60 L / s

Piping length = 17.4 km

Automated Screen

Sand Trap

Aeration Tank

Sedimentation Tank

Flocculation & Quick Mix

Sand Filter

Chlorine Disinfection

To Industrial Processes

MULTISTAGE WASTEWATER BIOLOGICAL TREATMENT PROCESS

BIOLAK WOX SYSTEM

MEAN CONCENTRATIONS OF WATER QUALITY PARAMETERS AT FRANCISCO I. MADERO MINING UNIT

PARAMETERS WASTE WATER TREATED WATER

BOD

TSS

TDS

pH

100 mg / l

42 mg / l

1,100 mg / l

6.8

15 mg / l

4 mg / l

1,100 mg / l

7

VIEWS OF THE WASTEWATER FACILITY AT MET-MEX PEÑOLES AND FRANCISCO I. MADERO

FRANCISCO I. MADERO AERATION AND

SEDIMENTATION TANK

MET-MEX PEÑOLES AERATION REACTORS

CONCLUSIONS

Treating and reusing water gives benefits such as:

• Less contamination of rivers, lakes, lagoons and consequently, ground water.

• Reduces costs for production facilities.

Treating and reusing water, changes customs, behaviors, values and habits of people towards water.

Education is vital to create water awareness among the population helping preserve rivers, lakes, wetlands and ground water.

Treating and reusing water add value to non renovable resources and lead us to towards a sustainable development.