Magali Campos (1)

7/29/2019 Magali Campos (1)

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QUALITY ASSURANCE IN THEPROCESS FROM ROCKS TO

CATHODES.Gerencia Funcional Ingeniera y Procesos

Vicepresidencia de Proyectos

Magali Campos B.


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INTRODUCTION

ALONG THE VALUE CHAIN OF THE

MINING BUSINESS, FROM ROCK TOCATHODES, MANY CRITICAL DECISIONARE BASED ON SAMPLES AND ASSAYS

(P. Carrasco et al 2004)


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THE ECONOMIC IMPACT OF CORRECTSAMPLING AND ANALYSIS PRACTICE

SAMPLINGWhat Happened when a Proper Sampling Device wasInstalled in a Tail Discharge?

Before the proper sampling device was installed thecopper tail grade was assumed to be 0,15 %, the realvalue was 0,2%.

The flow rate was 96.000tons/day.

The annual copper losses were 17520 ton/yearConsidering a copper price of 1 dollar/pound

The annual loss is 38.544MUS$


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THE ECONOMIC IMPACT OF CORRECTSAMPLING AND ANALYSIS PRACTICE

ANALYSIS PRACTICE

Some few years ago, Codelco decided to sell

51% of El Abra deposit. Due diligence processencountered assays were biased by - 0,06%Cu in the oxide zone. Because of the hightonnage and low grade of the deposit, impactof analytical bias caused economic loss of

300 MUS$


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QUALITY ASSURANCE

Define standards and procedures of thebest practices to ensure and confirm thequality, robustness and reliability of thegeo/mining/metallurgy base in order toobtain the economic benefits expected by

the project, helping to maximize long-term economic value of the Corporation.


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STANDARD, BEST PRACTICE GUIDESAND ANALYTICAL PROTOCOLS.

FUNDAMENTAL

ERROR

GROUPING &

SEGREGATION

ERROR

DELIMITATION

ERROR

PREPARATION

ERROR

EXTRACTION

ERROR


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IMPLEMENTATION OF SAMPLINGPROTOCOL

CNAM 008

HETEROGENEITY TEST TO DETERMINESAMPLING CONSTANTS ANDNOMOGRAMS FOR SAMPLE

PREPARATION


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SAMPLING CONSTANT


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CNAM - 007

STANDARD CONDITIONS OFSAMPLING STATIONS FOR MATERIALBALANCE AND TRANSFER POINTS OF

PRODUCTS


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SAMPLING METHODS

Manual, not equiprobabilistic Automatic Sampler


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CNAM - 017

QUALITY ASSURANCE INDIAMOND DRILL CUTTING


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CNAM - 011

INGAMELLS TEST

SUB SAMPLING IN A LABORATORY


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Keep the position (X, Y) for everyanalysis and put it into a graphic

Ingamells test


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STATISTICAL ANALYSIS FOR THE TEST


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CNAM - 015

SAMPLING AND CHEMICALANALYSIS OF COPPER CATHODES


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It is necessary to perform experiments to betterunderstand variability within cathodes, betweencathodes, and between processing units.

The correct sampling of copper cathodes is aprofound issue in the copper industry, worldwide.The determination of various impurity contents has

vast economic consequences for the copper cathodeproducers, and especially for the copper cathodeusers. F.Pitard (2002)


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STRATIFIED RANDOM SAMPLING


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PRESERVING SAMPLE INTEGRITY

CNAM - 012

STANDARD CONDITIONS TO FULFILLDURING SUBSAMPLING OPERATIONSAT THE LABORATORY


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PREVENTION OF ANALYTICAL ERROR

CNAM - 009

PREPARATION AND OBTENTION OFREFERENCE MATERIALS


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CERTIFIED VALUES FOR AREFERENCE MATERIAL

When using Atomic Absorption methods orother non absolute methods, the final outcomecorresponds just to a recommended value.

The certified value has to be obtained througha procedure where the result is a valueobtained from direct measurement of a

relevant parameter, traceable to a fundamentalunit in the International Unit System (SI).


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ABSOLUTE METHODMOLYBDENUM ABSOLUTE METHODARSENICABSOLUTE METHODCOPPER


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QUANTIFICATION OF ANALYTICALERROR

CNAM - 010

VERIFICATION OF CHEMICALANALYSIS RESULTS FOR MINERALS

CNAM - 013

QUALITY ASSURANCE IN PREPARATIONOF MINERAL SAMPLES FOR CHEMICAL

ANALYSIS


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Cu A % Cu B % Dif. Cu (A - B) %

PROMEDIO 0,4534 0,4538 -0,0004

VARIANZA 0,240 0,244 0,000092

DESVIACION ESTANDAR 0,490 0,493 0,0068

DATOS 410 410 410

ERROR MEDIO 0,00034

T -1,07

CV % 1,50

% ERROR SESGO -0,08


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WEIGHTING ERROR

CNAM - 014

STANDARD CONDITIONS OFWEIGHTING SYSTEMS FOR CONVEYORBELTS FOR METALLURGICAL BALANCE

AND TRANSFER OF MATERIALS


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CONCLUSION


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CONCLUSION

The application of standards and best practice guides, enablequality assurance of data for resource estimation, grade control,metallurgical balance and commercial transactions.

The Quality Assurance Analytical information is essential for thedevelopment of projects in the copper industry, the correctsampling and analysis practices give a huge benefit because theyeliminate hidden losses and maximize the available resources.

The use of standards help to maximize long-term economic valueof the Corporation, allow the company to maintain excellence ineverything we do and the practice of continuous improvement,makes us a world leader in the copper industry.


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PEDRO CARRASCO MENTOR OF STANDARDS

AND BEST PRACTICE GUIDELINES

Muchas Gracias

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Magali Campos (1)