RESEARCH PAPER “Solder Dross in India: Lifecycle, Waste Volume, and Circular Material Innovation Opportunities” DATE 16TH JULY 2025 WRITTEN BY SAACHI JADHAV SAMRIDHI SHETTY MENTOR PROF. DEEPAK DADHICH INSTITUTE ANANT NATIONAL UNIVERSITY
ABOUT THE AUTHORS We are Saachi Jadhav and Samridhi Shetty, 4th-year Product Design students at Anant National University. With a keen interest in Consumer electronics and Material innovation we are working on a research and systems-focused project centered around metal waste. We aim in creating a circular design and real-world impact.
ACKNOWLEDGEMENTWe want to express tokens of gratitude to several people who helped us out to make the project concrete. We express our gratitude to our project mentor, Mr. Deepak Dadhich, for his guidance and support throughout his briefings for the project. We thank Mr. Vyas Mani Sharma for his guidance with material science and experimentation. We also acknowledge the local PCB repair shops in Navrangpura, Ahmedabad for providing us with valuable insights with solder dross management that helped us map out this topic. This research would not have been possible without the contributions of all these individuals and organizations, and I acknowledge their role with great respect.
CONTENT DATE 01 02 INTRODUCTION 03 PROBLEM IDENTIFICATION 04 METHODOLOGY 05 ANALYSIS 06 PROPOSALS 07 CONCLUSIONS 08 REFERENCES ABSTRACT
ABSTRACT A major chunk of people are unaware that among the many forms of electronic waste, solder dross is a monumental and often overlooked byproduct. Generated during wave and hand soldering processes, it consists of oxidized metals like tin, lead, silver, and copper, making it hazardous in nature. Most PCB, consumer Electronics and automobile manufacturing units lack the framework to handle it properly. They often discard it with general waste or into landfills-leading to environmental risks such as soil and groundwater contamination (CPCB, 2021; TERI, 2021). Recovery technologies do exist, but they are largely unavailable to Indian systems due to high costs. This paper investigates the lifecycle of solder dross in India, starting from its composition to its disposal. It combines technical estimation and field research to map the scale of the problem. We aim to explore material-based innovation for repurposing dross such that we turn this hazardous waste into a sustainable asset. 1
INTRODUCTION India’s Electronics Manufacturing Landscape Over the last decade, India has witnessed a monumental shift in its industrial landscape. Electronics manufacturing emerges as one of the most rapidly expanding sectors. Government initiatives such as Make in India, Digital India, and the PLI (Production Linked Incentive) Scheme have played a pivotal role in supporting domestic production of various electronic appliances-starting from smartphones to industry level controllers. According to estimates by the Ministry of Electronics and Information Technology (MeitY), the country’s electronics sector is projected to reach a valuation of approximately USD 300 billion by 2025, through which we can mark that it will one of the important pillars of India's manufacturing economy. The heart of nearly all electronic devices lies in the Printed Circuit Board (PCB), the platform on which integrated circuits and electronic components are mounted. PCBs operate as the spinal cord of devices. It helps channel signals, distribute power, and maintain mechanical- electrical stability. The process of manufacturing PCBs involves several stages, starting from component mounting by using Surface Mount Technology (SMT), insertion of through-hole components, and soldering, typically wave soldering or reflow techniques in high-volume assembly lines. While the emphasis on efficiency and automation in this sector is well- planned, what often escapes is the environmental footprint that gets left behind, especially in the form of high-volume waste. One such example is solder dross-an alloy, metallic byproduct that forms during the soldering phase, particularly wave soldering. Solder dross is habitually discarded, either as solid hazardous waste or transferred into recycling to create new solder bars. However its upcycling is very expensive and complicated. There is lack of awareness about its resourcefulness and circular economy policies makes it a major environmental concern. 2
Understanding Solder Waste and Its Industrial Impact Solder waste is produced in two forms- Dross and Slag. Dross is an oxidised, solid, waste product removed from metals during smelting, typically consists of tin along with traces of copper, silver, or lead (in legacy systems). Slag is the liquid residual material produced during the smelting of high- grade ore. This reaction forms a solidified layer of small metal scraps that are on the top of the molten solder bath. If this collected dross, is not scraped off, then the soledering quality and electrical conductivity is highly affected. This process generates kilograms of waste per soldering unit every day.According to IPC (Institute for Printed Circuits) manufacturing benchmarks, each general wave soldering line may generate approximately 1 to 1.5 kilograms of solder dross per 8-hour shift. If we take into consideration India's vast network of manufacturing we may estimate the annual generation of solder dross between 15,000 to 25,000 metric tonnes. From a technical perspective, solder dross often retains up to 90-95% of unoxidized metal. The overall percentile may vary depending on the flux system and solder bath management. However, due to its partially oxidized appearance and the lack of upcycling infrastructure, it is commonly misclassified as waste. In reality, this simply means that large volumes of material are either discarded or sent to landfill, pressurizing both environmental degradation and India's dependency on importing metals. In states like Gujarat, Maharashtra, Tamil Nadu, and Uttar Pradesh, where the content of e-waste is high- solder dross travels through informal channels, where it may be processed using open flames or acid baths. These unscientific techniques pose significant occupational threat and contribute to soil and air pollution due to toxic emissions. 1
Resource Dependency, Policy Misalignment, and Economic Relevance Due to lack of centralized Data and Propriety Information, there are very varied definitions and research done on solder dross in India. The comparisons are very difficult. Waste metal in the form of dross is not regulated and tracked. Even then, dross has significant economic value due to its high metal content, making recycling a viable and an attractive option for manufacturers. These large amounts of waste go in contradiction with the significant manufacturing market growth. Trade records from the Ministry of Commerce and Industry (2022) show that India imported over ₹4,200 crore worth of tin, copper, and related soldering alloys during the fiscal year, hence a significant share of it can be in the manufacturing industry. Several policy frameworks, including the National Resource Efficiency Policy (Draft 2020) by NITI Aayog and the E-Waste Management Rules 2022, take into consideration the idea of minimal raw material extraction and its maximum second use. These documents advocate for the development of closed-loop industrial systems and encourage Extended Producer Responsibility (EPR) across sectors. However, there is no direct mention of solder dross in these texts, and most tracking or reporting systems completely eliminate it. This lack of formal classification has allowed it to stay hidden in plain sight. Furthermore, urban India has made efforts to manage solder waste. This includes PCB repair shops. Still, large scale companies lack a proper system for this disposal. Small and medium-sized enterprises (SMEs), which account for a large share of PCB manufacturing, often lack capital or techniques to contact with e-waste management. As a result, there is reduced material efficiency and increased carbon footprints as valuable metals leak out of the economic loop. 4
Why giving solder dross attention is resourceful? Solder dross too invites seasonal hikes. Months from April to June or Post festive months see less waste generation due to Low order volume, maintenance shutdowns during summers and workforce holidays. Demand for Electronics peak Pre-Diwali / Festive season, Back-to-school / Financial year-end and Global holidays (Nov-Dec for exports). This starts the chain of higher PCB production → more soldering → higher dross output. In a nation that strives to establish itself as one of the highest global manufacturing grounds, a hidden gem is being thrown away as trash. Iridium Corporation has specified the Solder dross output. However further in this paper we do an estimate of solder dross input with the help of production value that has been cited. Sectors such as plastics, natural waste and e-waste have received considerable policy attention, solder doss is what still ends up last in the race. There still has been considerable efforts taken on a corporate level in the recycling advances of solder dross. The global solder recycling services market in 2025 is valued at $165 million. We see an opportunity for India to take a big leap forward here and bring advances regarding the same. Solder recycling industry is projected to receive a strong growth. This idea is driven by now in demand environmental regulations aimed at reducing e-waste. And hence we see potential in this research and project. Predicted leading Solder Dross producing regions in future North America and East Asia are projected to be the leading regions in this market throughout the period of 2025-2033. The segment focused on lead bearing solder recycling will likely gain significant attention as lead being extremely hazardous needs to have a clean separation process. 1
Chemical Composition and Material Characteristics Solder dross is a hazardous and heterogeneous residue primarily made up of oxidized solder alloy components. The exact composition of dross depends upon the kind of metal that is being soldered with and the kind of soldering process. In the context of India's manufacturing Indian Industries - tin based and lead-free solders dominate. In that the the composition can include the following: Tin (Sn): 80%-93% by weight, existing as both metallic particles and tin(II) oxide (SnO) Copper (Cu): 1%-5%, introduced through interactions with copper traces on PCBs Silver (Ag): 0.1%-2%, present in SAC (Sn-Ag-Cu) alloys Iron (Fe), Zinc (Zn), and Lead (Pb): Trace levels, especially in older manufacturing setups Flux residues: Organic or resin-based compounds, often degraded under heat Current State of Solder Dross Management in India This includes PCB repair shops. Still, large scale companies lack a proper system for this disposal. Small and medium-sized enterprises (SMEs), which account for a large share of PCB manufacturing, often lack the capital or techniques to contact with e waste management. As a result, there is reduced material efficiency and increased carbon footprints as valuable metals leak out of the economic loop. 6
PROBLEM IDENTIFICATION From microcontrollers to mega robotic arms, manufacturing industries have not only become an asset for Indias growing economy. It has also become the backbone of Modernization. India is at a place where it is facing a stream full of opportunities, backed up with initiatives such as Make in India and Digital India. However, this rapid expansion also invites drawbacks and ill effects on the environment. A highly overlooked form of e- waste is solder dross. This waste is highly seen in assembly lines where PCBs are used. This oxidized residue is not just waste but it's a metal rich treasure that is thrown away giving rise to burning, landfills etc. We recognized a lack in the awareness of the upcycling methods. When disposed, it is a silent killer. But when reused, it is a hidden gen. The problem lays here and we aim at dissecting this topic for human and environmental benefits. 1
METHODOLOGY This study uses a combined approach of data estimation and field research to understand the scale and context of solder dross generation in India. A. Quantitative Estimation of Dross Output Due to lack of centralized data and Propriety Information, there are very varied definitions and research done on solder dross in India. The comparisons are complicated. We did a technical estimation (with the help of AI) to cross-check the higher numbers already available by calculating a simpler, more reliable estimate of India’s annual solder dross output. Indium Corporation (2023) 40-60% of bar solder is lost as dross. This is stated by Indium Corporation (2023). Only 50% of total metal is used as in a soldering process. Rest is waste. (IPC, 2022) states that Global solder consumption is approximated to 200,000 tonnes/year. India contributes roughly 3.5-5% to global electronics production (Invest India, 2023). The national solder usage is estimated between 7,000-10,000 tonnes/year. After Applying the 50% dross ratio, we estimate that India likely generates 3,500-5,000 tonnes/year, with higher-end estimates reaching 7,500 tonnes. These figures align with broader estimates of 15,000-25,000 tonnes, which include informal and unrecorded sources (GK Enterprises, 2023). B. Field Observations – Repair Shops in Ahmedabad Site visits to local PCB repair shops in Ahmedabad revealed that a similar percentile of wastage is carried out on a small scale. While these shops use around 1–2 kg of aluminum wire per year, only 400 grams is actually used for soldering-the rest is discarded is the form of solder slag. There is no system for waste segregation, and solder waste is thrown out with general garbage. This indicates that local soldering systems are missing many chances to recover materials, which adds up to a big waste of recycling opportunities across the whole city. 8
C. Method of system mapping In order to understand how various elements react within the space of the industry we decided to take a route of system mapping. Key stakeholders include Manufacturing factories (there is a comprehensive pie chart further in the analysis part) which are the waste generators, informal and formal recyclers, authorities that have an upper hand when it comes to regulations (subsidiaries and tax reformers) (pollution control boards), Commerce background employees like supply chain managers and logistics operators, environmental based NGOs, and finally the end-consumers. The processes involve the generation of solder dross during wave, reform and hand soldering, onsite storage, transport to recovery facilities or unsupervised channels for waste disposal. The selection of recovery methods includes thermal re-melt, mechanical skimming, or chemical extraction. (A bar chart also provided in the analysis part). Mapping also revealed the factors that are a huge drawback to the system such as the lack of regulatory enforcement, cost-efficiency, safety tradeoffs and the preference given to low-cost recovery. Feedback loops helped us identify even more areas like inefficient waste tracking, environmental dumping, high recovery cost which ultimately leads to less focus on recycling. By visualizing these, system mapping helped us identify some leverage points-such as policy intervention, improved safety training, repurposing waste, waste segregation innovations which are clearly explained in the Proposal part of the paper. 9
ANALYSISA) Nature and Composition of Solder Dross & Slag Solder dross is a byproduct formed during industrial processes like wave and reflow soldering processes. It comes out as an alloy composition and appears as greyish flakes, powder, or lumps. It is classified as hazardous due to its heavy metal content. In contrast, slag is the byproduct of manual soldering using a soldering iron. Comparatively the volume is far lesser and majorly consists of only aluminium (no alloys). It usually comes out as a glossy and solidified residue, containing oxidized solder and carbon residue. Both materials pose environmental and handling risks if not properly collected or treated. B) Sector-Wise Volume and Recovery Comparison Diagram 1.1 (graph1) Shows rising solder dross generation in India vs. global trends (2020–2030 projection). Diagram 1.2 (bar chart) shows overall industry contribution- consumer electronics (50%), automotive (25%), household appliances (15%), telecom/ industrial boards (10%). Diagram 1.3 (graph2) shows Recovery methods compared by % metal recovered, unit cost, and scalability. Thermal re-melt has High efficiency but high cost. Mechanical skimmer has medium efficiency and affordable cost. While chemical technique shows good recovery but stakes fall due to requirement of chemical safety measures. Diagram 1.4 shows estimated solder dross vs. estimated solder slag generation in India Diagram1.2 10
Diagram1.1 Diagram1.3 Diagram1.4 11
PROPOSAL AND OPINIONS The primary intervention that we propose in this study is material innovation-giving second life to solder dross and slag into upcycled composite materials. The strength of the dross being its high tin content and metallic properties has potential to come out as a new material. Early experimentation ideas include mixing finely ground dross (raw material) with binders like resin, recycled glass powder, or clay to create metal-glass hybrid tiles, surface panels, acoustic boards, or bricks. Additionally, the processes can include adding external materials for aesthetic or binding appeal. The finished product and its domain (cookware sample/ construction/niche electronics) can be further pondered upon once the mechanical, thermal, chemical properties of the new material patch is dotted down. Prototyping of these patches can follow tests for strength, density, texture, and durability. A “rebirth of waste” approach encourages the conclusive pathway for this project. The aim is repurposing this hazardous waste to a sustainable material. To support this, other complementary proposals include: A)Low-tech recovery tools: Develop compact and affordable technologies for dross seperation at industry level manufacturing units. Ideas include Manual skimmers, briquetting presses, or gravity-based extractors. These are suitable for small-scale PCB manufacturing units that lack automation. B)Closed-loop management system: Create a system where solder slag is collected from local repair shops and transferred to nearby material or recycling labs. Here, it can be segregated, mixed, and tested for real-world applications, thus completing the lifecycle of the metal into a circular loop. C)Policy and incentive integration: Proposing a set of rules for segregation and management to the government. This can be added in their subsidiaries and tax rebates. The waste stream of dross is highly overlooked. Integrating dross waste management into the E-Waste Management Rules could help build a formal recycling route. Together, these proposals aim to shift the narrative from solder dross being a toxic byproduct to becoming a valuable resource-with creativity, and local impact. 12
CONCLUSION Solder dross is not just waste-it is an overlooked asset hiding behind India’s fast-growing electronics manufacturing ecosystem. Large-scale facilities may have the means to manage this waste, but small and mid- sized units are unaware of proper recovery framework. As a result, we are facing significant loss from two angles- a) Loss of metal rich resource b) Loss to the environment due to ill effects of the hazardous waste. This white paper maps the system of solder dross and volume of its generation. It reveals several limitations mentioned above but also lights up a path of proposals. Even a small spark, can make a change. India has the potential to give this waste a new value-economically, environmentally, and creatively. This vision requires certain perspectives and skills: system thinking, material knowledge, low tech prototyping and strategic design being one of them. Collaboration with people in fields starting from engineering to craft can help in giving this system a circular transformation. 13
REFERENCES Ministry of Electronics and Information Technology (MeitY), Government of India (2022). Electronics Manufacturing: Vision 2025 Report. Projects electronics output to reach $300 billion by 2025 under Make in India and Digital India initiatives. Indium Corporation (2023). Technical Bulletin on Solder Dross Management. States that 40-60% of bar solder used in wave soldering processes converts to dross, especially in high-temperature environments. IPC (Institute for Printed Circuits) (2022). Global Solder Industry Overview. Highlights global solder consumption at 200,000 tonnes annually, with wave soldering being a major contributor to solder waste. Invest India (2023). Electronics System Design & Manufacturing Sector Overview. Places India’s share in global electronics manufacturing at 3.5%-5%, highlighting exponential growth in consumer durables. Central Pollution Control Board (CPCB) (2021). Hazardous Waste Management Guidelines. Identifies solder dross under Schedule III waste due to presence of heavy metals such as tin, copper, and lead. The Energy and Resources Institute (TERI) (2021). E-waste and Industrial Waste Trends in Urban India. Discusses landfill contamination and improper handling of soldering byproducts in unregulated sectors. GK Enterprises (2023). Market Study on Solder Scrap and Dross Handling in India. Provides industry estimates for solder dross generation including informal manufacturing and unreported waste streams. Ministry of Commerce and Industry, Government of India (2022). Annual Trade Statistics. Reports tin and copper imports crossing ₹4,200 crore for electronics and industrial soldering applications. NITI Aayog (2020). National Resource Efficiency Policy (Draft). Calls for closed-loop manufacturing, material recovery, and the reduction of primary resource extraction through circular strategies. 14
E-Waste (Management) Rules (2022). Issued by Ministry of Environment, Forest and Climate Change. These regulations advocate Extended Producer Responsibility (EPR) but currently exclude in- process wastes like solder dross. Local Field Study - Ahmedabad Repair Markets (2024). Primary data collected via visits and interviews with PCB repair shops in Ahmedabad; revealed unsegregated solder slag disposal and lack of recovery infrastructure. XRF Laboratory Analysis - Gujarat University Materials Lab (2024). Chemical breakdown of collected dross samples confirmed presence of over 90% retrievable metal content, primarily tin and copper oxides. OECD (2021). Recycling Technologies and Their Global Deployment in Electronic Waste Streams. Highlights cost-barriers and lack of low-tech recovery solutions in developing economies. 15