MINING EFFLUENT VALORISATION: HOW A PROBLEM BECOMES A VALUE RESOURCE Estanislao Martínez Martínez CEO AGQ Labs & Technological Services Manuel José García Gómez CEO AGQ Mining & Bioenergy

MINING Geological Exploration, Mining and Metallurgy Analytical Characterization Metallurgical Tests Assays Environmental Solutions: feasibility, diagnosis, monitoring and rehabilitation studies BIOENERGY Biomass production, with an environmental or energetic purposes, employing effluents and/or contaminated lands. Based on a great knowledge of agronomic process and by application of advance techniques for water and soils treatment, an environmental concern can be solved and also goods production achieve. It can be a biomass fuel production, or a landscaping or an environmental

HUELVA RIOTINTO MINING AREA BETWEEN RIVERS TINTO AND ODIEL

Tarthessus original habitants Phoenicians Romans Visigothic Moorish British / French Spanish Differents Civilizations involved in Mining Operations since ancients times Cu and Ag Pyrite (sulphuric acid) Pyrite, Cu, Au,… A HUGE LANSCAPE ALTERATION

ORIGIN OF THE PROBLEM ACID MINE DRAINAGES NATURAL ORIGN (RiverTinto) LIQUIDS WASTE AND EFFLUENTS OF METALLURGICAL PROCESSES

Concentration River Tinto 37º40´21”N 6º32´29”W River Odiel 37º35´45”N 6º50´37”WUnits pH Ud C.E microS/cm As mg/L Cd mg/L Cu mg/L Fe mg/L Mn mg/L Ni mg/L Pb mg/L Zn mg/L SO mg/L Typical River Odiel and River Tinto quality comparison, in the proximity abandoned of mining operations and in the coordinates given

CHEMICAL WATER TREATMENT ACID MINE DRAINAGE Neutralization with alkaline hydroxides Separation of colloids and precipitates Acidification to pH=6.5 FERTILIZATION TREATMENT Ammonium salts Potassium salts REAL FERTILIZER SOLUTION FROM ACID WATERS TO REAL FERTILIZER SOLUTIONS

Treated acid mine waters ConcentrationUnits pH 6.50 ud C.E microS/cm SO mg/L Cl mg/L NO mg/L PO 4 H mg/L Ca mg/L Mg mg/L Na + 40 mg/L K+K+ 0.3 mg/L Cu mg/L Zn mg/L B-B- 0.2 mg/L

TESTING SITE The research area was located in Burguillos (Sevilla, SW Spain), 37º35´41”N 5º58´55”W. Soils are very calcareous, alkalines (pH: ), with low organic matter content (<1.5%).

The research plot area was of 1 Ha with a planting density of 3330 plants for Ha. Each line was equipped with a series of irrigation emitters with a designed flow of 1.6 L/h and spaced 1 m apart (Total irrigation flow of 10.6 m 3 /h/ Ha). Eucalyptus globulus and Eucalyptus camaldulensis

* Monitoring and control of crops under technified irrigation * Optimization of fertilizer solution use and water requirements * Optimization of the leaching fraction (Minimize environmental impact) Focus Controlled Production Differential Objective QUALITY TECHNIFIED CROPS WITH AN AGRONOMIC CONTROL

SOIL-PLANT-WATER SYSTEM The roots absorb soluble ions from soil solution

SamplesCEpHPO 4 H 2- Cl - SO 4 2- NO 3 - NH 4 + Ca 2+ Mg 2+ Na + K+K+ mS/cm 25ºC(ppm)(meq/L) Real Fertilizer Solution S.Probe at 20 cm S.Probe at 40 cm < S.Probe at 60 cm < Sampling Program Results in May 2010

SamplesCEpHPO 4 H 2- Cl - SO 4 2- NO 3 - NH 4 + Ca 2+ Mg 2+ Na + K+K+ mS/cm 25ºC(ppm)(meq/L) Real Fertilizer Solution S.Probe at 20 cm S.Probe at 40 cm < S.Probe at 60 cm < Sampling Program Results in Septembre 2010

Foliar analysis Eucaliptus leaf levels %N vs. Grow rate

In both cases is observed: A.- High plants absorption, by means of consumption, of main nutrients ions (N, P, K). B.- A relevant water absorption was found in the first sampling is observed, with no absorption effect of ions, especially Cl - and Na + ; with a possible toxicity risk comprehend with N and K concentration. As result an increase of salinity due to the low irrigation flow is observed, and as consequence, a minor metabolic activity is reached. C.- In the second sampling analysis such a problem is minimized after increasing the flow coefficient. Is also observed in less concentration of toxic elements, Cl y Na, in foliar analysis. D.- An increase of Ca 2+ in soil depths by limestone dissolution and a buffer effect with high pH. A more favorable Ca/Na relation in second sampling and less peptization risk. F.- In both cases the chemical composition of solution at high depths is not pollutant and has no environmental restriction.

- Valorization of industrial effluents: chemicals, agrofood, mining, etc... - Development and monitoring in energetic crops (Biomass, Biofuels)… AGQ Experience - Assessment of more than hectares in Mediterranean area, North Africa, Caribbean, California and South America. - Monitoring, control y rehabilitation of contaminated lands. - Recuperation projects of saline soils in Spain (Ca/Na), River Nilo/Egypt, Copiapó (B) y Arequipa (Ba, Sr) … - Green areas.

HOW A PROBLEM...

... BECOMES A RESOURCE

VIA ENERGETIC CROPS AND MONITORING CONTROL

VALORIZACIÓN EXCEDENTE DE AGUA Ciclo Completo Mining Operations Effluent from Process or AMD Treated Effluent Energy Generation Agronomic Project Energetic Crops Biomass Fuel Electric Energy Thermal Energy Restoration VALUE Self Energy Clean Energy Reduction CO 2 Image/Social

ADVANTAGES SOLUTIONS OF EFFLUENTS AND DEGRADED MINING AREAS ENVIRONMENTAL SUSTAINABILITY ECONOMIC BENEFITS FROM ENERGY PRICES AND SELF-SUFFICIENCY POSITIVE ENVIRONMENTAL IMPACT OF CO 2 EMISSIONS REDUCTION IMPROVING GLOBAL IMAGE OF MINING ACTIVITIES SOCIAL BENEFITS, EMPLOYMENT GENERATION, ALTERNATIVES OF OTHER ACTIVITIES. KEY ISSUES WATER TREATMENT PROCESS MANAGING AND CONTROL OF SYSTEM WATER - SOILS - PLANT IN ENERGETIC CROPS BIOFUEL MANAGEMENT

Irrigation Water Energy Production 1 MWe 0.60 Hm MWh/y Energetic Crops Lands 250 Ha Biomass Annual estimation t/y emissions reductions 5800 t/y CO 2