This book is the outcome of research-investigation in converting wastes-to-wealth on certain minor and valuable metals in the wastes/residues generated in Zinc-Lead Smelters on the inspiration from Dr. V. K. Saraswat, Member, Niti Aayog in his address on 15 July 2021 on the “Indian Nonferrous Metal Industry”.

Salient Features

• The methods presented in this book can be used for wastes/residues in other non-ferrous metal industries too and not restricted to Zinc and Lead Smelters.

• Focusses on the recovery of important minor and valuable metals present in the solid wastes at Zinc-Lead Smelters through innovative technologies of converting “Wastes to Wealth”.

• Starts with the recovery of lead, silver and manganese from the anode mud generated at the electrolytic cells during the electrowinning of zinc where the liquid effluent containing sulphur dioxide was found to be a potential leachant to recover metal values for the wastes/residues.

• Incorporating a similar scrubbing system using sodium carbonate as a scrubbing agent at the stack which wouldprovide a clean environment (SO2 with permissible from the stack at all times) and generate a useful leachant for the leaching of the wastes generated at the smelter complex to reduce solid waste generation. solid wastes generated at the Zinc-Lead Smelter complex.

• Adopts a novel approach for the recovery of zinc present in the ETP Sludge to produce zinc metal powder with the flow sheet adopted which would provide a reduction in solid waste generation.

• Includes a brief on certain minor metals such as gallium, germanium, indium, and mercury.

• Describes the application of chemical treatment to the zinc dross generated at melting cathodes for the recovery of zinc as well as metallic zinc.

• Provides the basic chemistry, metallurgical aspects and flow sheet developed for each metal.

RECOVERY OF MINOR AND VALUABLE METALS FROM WASTES AT ZINC-LEAD SMELTERS

ABOUT THE AUTHORS

R. Raghavan

Obtained PhD from the Mohan Lal Sukhadia University of Udaipur in Chemistry and AMIIM (Graduate in Metallurgical Engineering equivalent) from Indian Institute of Metals, Kolkata. A Professional Chartered Chemist and Metallurgist with a background in production, operations, research, and development. A proven record of accomplishments at each stage of his career.

Published more than 45 Scientific and Technical papers/publications in process metallurgy and process analytical methods. Published three books: “Chemical Analysis in Non-ferrous Extractive Metallurgy”, “Extractive Metallurgy of Non-ferrous Metals”, and “Analytical Testing Methods in Non-Ferrous Extractive Metallurgy”. The book “Measurement Uncertainty and Methods Validation in Chemical Analysis” is under print.

Presently Associated as Chief Advisor in Non-ferrous Metallurgical Research Foundation devoted to the wastes generated in non-ferrous metallurgical industries to convert and produce value-added metals and developed pilot plant-proven technologies.

Member of Professional bodies such as the Indian Institute of Metals (Life Member), and the Indian Association of Analytical Scientists (Life Member) and a member of the Royal Society of Chemistry, ASTM International and Chartered Chemist (CChem) from the Royal Society of Chemistry and Vice Chairman of the Royal Society of Chemistry (South India) till 2021.

Empanelled as Technical Assessor with the National Accreditation Board for Testing and Calibration Laboratories (A Constituent Board of Quality Council of India) in chemical testing (both classical and instrumental methods).

Delivered an expert lecture covering the topics of Extraction of zinc, lead, cadmium, and silver as well as Chemical Analysis in Non-ferrous Extractive Metallurgy at the invitation of the Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal, Mangalore during October 2017.

Paper presented on “Make in India” Technologies-Innovation Contribution by in-house Research and Development Centre of Vizag Zinc-Lead Smelter, Hindustan Zinc Limited (A Government of India Enterprise)” at NMD-ATM 2017 during November 2017 at Goa and delivered a Keynote address on “Redefining the wastes processing and recovering metal values from non-ferrous metallurgical industries” during NMD-ATM 2018 at Kolkata.

Delivered an Invited lecture on the ”Application of Electro-Analytical Techniques in Mining and Metallurgical Industries” organized by the Indian Analytical Science Congress IASC 2018 at Backwater Ripples Resort, Kumarakom, Kottayam in February 2018.

P. K. Mohanan

Graduated (1967) from Kerala University in Chemistry. He started his career in Cominco Binani Zinc Ltd, Cochin, Kerala in 1968 and was associated with the R and D Department for 10 years. He joined Hindustan Zinc Ltd at Visakhapatnam Zinc-Lead Smelter Complex at R & D and worked for 23 years. During his association, he has done extensive research work related to zinc and lead metallurgy and valuable contribution to ‘waste to wealth technology’. He has presented many technical papers in national seminars and is also a co-author of various technical papers in national and international journals. Later he joined as General Manager (R&D) at Biota Agrosolutions Pvt Ltd, Cochin and has developed many copper-based fungicides during his 17 years of tenure and modified many process flow sheets to meet the present needs.

RECOVERY OF MINOR AND VALUABLE METALS FROM WASTES AT ZINC-LEAD SMELTERS

Dr. R. RAGHAVAN
P. K. MOHANAN

Vijay Nicole Imprints Private Limited

CHENNAI

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Dr. R Raghavan

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Chennai 600050, India

Email ID: dr.r.raghavan@gmail.com

Recovery of Minor and Valuable Metals from Wastes at Zinc-Lead Smelters

ISBN: 978-93-95245-68-5

EPub: 978-93-95245-70-8

EPdf: 978-93-95245-69-2

COPYRIGHT © 2023, Authors

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Laser typeset at: Maven Learning, Chennai - 600 091.

DEDICATE THIS BOOK TO OUR MENTORS

(Late) Dr. G Prem Kumar
Shri K S Koppiker

CONTENTS

About the Authors

Foreword

Preface

Acknowledgements

Introduction

1. Anode Mud – Resource for Lead, Silver and Manganese

2. Anode Slime – Resources for Precious and Minor Metals

3. Antimony

4. Cadmium

5. Copper

6. ETP Sludge – Production of Zinc Metal Powder

7. Lead – Process Options from Lead-Bearing Materials

8. Minor Metals Recovery – Gallium, Germanium, Indium, Mercury

9. Nickel

10. Zinc Dross – Recovery of Zinc and Metallic Zinc

11. Two-Stage Effluent Treatment

Conclusion

Our Mentors - Brief Bio

Poem on “Hydrometallurgy of Zinc” – as practised in 1987

Subject Index

FOREWORD

It is indeed very rare that executives in the industry think of writing books mainly because of their day-to-day priorities or because they do not possess writing skills. And it is all the more very rare that retired executives from the industry ever think of writing books since they want to lead a quiet and peaceful life with their families.

The author of this book, Dr R Raghavan is an exception to the above facts; he has an unlimited penchant and passion for sharing his rich knowledge & wide experience, for the benefit of future generations. He has authored several books on Nonferrous Extractive Metallurgy, Analytical & Testing Methods etc. besides presenting thought-provoking technical presentations at numerous conferences.

Today the contemporary world is talking about “Waste to Wealth” and therefore it is laudable that Dr Raghavan carried out so many research projects during his career in the ’80s & ’90s, both lab scale as well as plants scale, for the recovery of critical & strategic materials like Gold, Silver, Cadmium, Antimony, Nickel, Copper, Lead & Zinc as well as minor metals like Gallium, Indium, Germanium, Selenium etc. This truly indicates Dr Raghavan’s future vision & emerging trends.

I must also place on record my sincere appreciation to the co-author of this book, Mr P K Mohanan (who also had long innings in the Lead & Zinc sector) for providing a big helping hand to Dr Raghavan. The poem-very unique – by Mr Mohanan is truly creative and constructive.

And finally, let me wish this book all success and a great reception among the readers’ community.

L. Pugazhenthy

Past President (2008-09)

The Indian Institute of Metals &

Executive Director India Lead Zinc Development Assn.

New Delhi