Lead recycling process is of great interest in the lead industry. Nowadays, more then 50% of the overall world lead production comes from secondary lead smelters. The main raw material for this process are used lead-acid battery ( ISRI Rains) and lead scrap ( ISRI Radio). Roughly, about 90% of scrap batteries are recycled.

Lead has one of the highest recycling rates in the world, higher even than better known recycled objects such as paper or glass. It is also the most recycled metal of all those commonly used, far greater than copper, aluminum, or zinc.

 Lead recycling makes a significant  contribution  to sustainable development, easing the pressure on non-renewable resources and reducing carbon emissions through a simple and energy-efficient recovery method.

Lead Recycling Process includes these following steps:

1. Lead Battery Breaking and Separation
2. Lead Smelting
3. Lead Refining and Alloying
4. Lead Casting

1.Lead Battery Breaking and Separation

It is used Lead acid scrap batteries are received through container/trucks will be unloaded at the battery recycling plant, from where batteries will be processed through breaking and separation system. These scrap batteries are crushed in the hammer and the output is passed through a sieve conveyor to clean off and separate the Lead Oxide powder. After this Lead and plastics are separated in sink and float tanks. The PP and PE are also separated inside the last tank. The entire system is a closed loop, and the water is re-circulated after passing through a filter press. An acid neutralization system is also used to treat the water before re-circulation

2. Lead Smelting

Lead Smelting is the process of separating the metal from impurities. It is placed into a furnace where it is heated by
high temperature. It causes the metal to melt. Smelting the raw material produces a metal or a high-grade metallic mixture along with a solid waste product called lead dust and toxic slag.

 

3. Lead Refining and Alloying

The lead received from Furnace (smelting) is called hard lead /crude lead. The lead tapped from the furnace has to be cleaned from residual oxides and slag. After stirring for a while all the impurities settle at the surface and are skimmed off. Lead recovered via blast furnace contains a lot of contamination and undesired components. On the other hand, Lead required for battery manufacturing is either soft Lead with 99.97% purity or hard Lead of varying Antimony compositions. In order to make the quality of lead suitable for its different uses, different variations of pot melting processes are employed.

Lead is melted within the pot; components, which include Sulphur, Wooden Powder & Coke Breeze, are added and blended gently followed by dross removal. Thereafter, Tin & Antimony are added to the liquid metal to get the desired grade of Lead.

 

4. Lead Casting

Casting Machine does lead Ingot Casting. This machine is a combination of chain conveyor mechanism. The moulds are filled with Pure Lead with a lead pump or through flow regulating valves. The feeding system has load cell mounted, which controls the speed of the Lead pump and it regulates the flow of lead automatically.

The ingot stacking process is used after the casting system to continuously make a stack of Lead ingots, which can be strapped and handled by forklifts. This machine saves labor and makes the operation quicker and convenient.

 

Lead
Refining Process

Lead Refining, producing Lead with a minimum purity level of 99.97% from Smelting furnaces tapped crude Lead. Company supply Refining Kettle Furnaces of various capacities ranging from 5-100 tones per batch, accompanied by high efficiency natural gas / LPG burners / furnace oil burners, equipped with preheating arrangements. Emissions are controlled by a flexible kettle hood, with series of Pollution Control Equipment’s chained with Wet Scrubber, attached to an Induced Draft Fan along with a chimney/stack arrangement. The refining unit complement is completed by the automatic Lead ingot-casting machine (with Lead-Pump) having a production capacity of up to 10-20 MT/hr. Refining unit package is optimally configured for high throughput with good emission control, as proven by the existing installations in operation.

Lead Oxide Manufacturing

There are two oxides of Lead with commercial applications:

• Lead Sub-Oxide (2PbO.Pb.H2O), also known as Grey/ Lead Oxide,
• Red Lead Oxide (Pb3O4) or Lead Ortho plumbate.

        

Red Lead have a Barton plant as the common first step. The required input is refined Lead ingots of 99.97% purity. The Barton plant output is routed to either the Red Lead furnace with their respective equipment complement. 

The Barton plant comprises of a small Lead melting furnace, operating inline with a Barton Reaction Pot with stirrers, classifier, cyclone, filter bag-house, ID Fan arrangement, together with a collecting bin and material handling systems. The final Red Lead plant module utilizes the Barton plant module output, as its input. It comprises of a Red Lead furnace, in conjunction with a dust collection plant, conveyors, grinder and cyclone-bag-house filtration unit arrangements, culminating in a packing and storage module.