LEAD OXIDE POWDER MAKING PLANT
Ball Mill Process - Lead pigs, or ingots are charged with air into a ball mill. Frictional head generated by the tumbling lead ingots initiates and oxidation reaction. Oxygen in the air, assisted by the heat of the tumbling lead, reacts with the lead to produce lead oxide. During milling, the lead oxide that forms on the surface of the ingots and fine particles of un-oxidized lead are broken off, forming a fine dust that is removed from the mill by a circulating air stream. Centrifugal mills and cyclones are used to collect large particles, while the finer particles are collected in a baghouse.
a) Rotating (drum): It is closed cylindrical drum, made of steel. The process of colliding lumps/cylinders with itself and wall of drum, and reaction with oxygen occurs inside this closed drum.
b) Transmission group: The rotation of the drum is done by means of a reduction gear group, which transmits the motion to the pinion and crown, which is connected to the rotating drum. Transmission system is driven by main motor through multi-belt and pulley.
c) Lubricating system: The centralized lubricating system, which supports all moving parts, the main motor and transmission system .The pinion and crown lubricating system is done automatically by means of a specific pump, which greases the kinematics motion following the time set in the PLC of the machine.
d) Cooling system: The Mill inside temperature is adjusted by means of an outside water circulation and by airflow, sucked by a fan positioned on the hood. The temperature adjusting is assured by thermocouple that gives the temperature value and by means of the PLC, which starts the cooling system if necessary.
e) Protection hood: In stainless steel assures a suitable protection to the moving parts and enables to collect the cooling water sprayed on the outside part.
f) Weight and Temperature controlling system: Three temperature probes fixed at three different locations inside the body of drum. Mill has a weighing device under the main mill, which indicates the weight of powder /oxide inside the mill .The feeding lead lumps amount depends on this weight.
Pulsaire Collectors/Filters
Lead oxide is harvested through a classifier high efficiency cyclone, bag-house filtration unit or Pulsaire collector and induction draft fan arrangement. Fine particles of powder enter into Pulsaire Collector /filter unit. These particles are then filtered through the vacuum cylinders/filter bags leaving its fine particles deposited on their outer surface. Meanwhile, the high-pressure air pulses effectively dislodge the deposit of these fine particles from the filter bag's surface and cause it to fall to the collecting hopper. The collecting hopper is connected with conveying system, which transfers oxide powder to oxide storage silos.
Conveying System & Oxide Storage Silos
The lead oxide powder is transfer to oxide storage silos by using multi-type conveying system, which is combination of snake conveyor, screw type conveyor and bucket elevator. The system is designed for smooth transfer of powder without leakage of dust in surrounding or working environment.
Snake Chain Conveyor conveys oxide through carrying blades attached to two strand special chains in an enclosed casing. Oxide conveyed between carrying blades, which make independent chambers without being stirred up.
There are three oxide storage silos of capacity 40 ton each. The digital weighing meter/indicator on silos shows the quantity of oxide present in silo.
LEAD OXIDE MAKING PROCESS
Lead oxide is (Pbo/Pbo2) is used in lead acid storage batteries as active mass. There are three lead oxide plants in ABL. The total production capacity oxide is about 25 ton daily/24hrs. The lead oxide making plant comprises of four main units
· Lumps making and storage silos
· Oxide mill
· Pulsaire collector/filter unit
· Conveying system and storage silos
Lumps casting/making:
Imported refined lead 99.97% is first melted down in furnace at about 320C. Then molten lead is sent through a pre-heated tube into the cylinder crown cavities by a centrifugal pump .
The lead quantity is adjustable by opening/closing the lead plug cock/adjusting screw or adjusting the machine rotation speed. The cam near the cylinders unloading pushes up the extractors and ejects the lead cylinders /lumps into a chute leading to buckets elevator, which feeds the cylinders /lumps storage silo. The cooling system solidifies the melting lead before the ejection enabling the transport by means of bucket elevator, to the cylinder silos.
Lead Oxide Mill Process
Lumps from storage silo, automatically fed into oxide mill. In the ball mill, Lead is converted to Lead Oxide, by grinding and oxidation process, which is an exothermic process. In this process, heat is generated and temperature of oxide is increased, to control the temperature with in the operating range of 115 to 135C, the ball mill temperature is controlled with constant flow of air and with the water spraying system controlled through solenoid valve. The fine particles of lead oxide remaining in the air stream are drawn out of the Ball Mill and conveyed into the Pulsaire Collector
Pulsaire Collectors/Filters (Operation and purpose):
The purpose of Pulsaire/filter unit comprises of following two factors.
1. The first one is to keep under vacuum all the system (mill) and not to have any dust emission on the working environment
2. The second one is to extract the lead oxide powder from the rotating chamber (where grinding and oxidation of the metal are done simultaneously) and bring it to the hopper of the cyclone filter from where it is mechanically sent to the oxide silos by conveyors.
The desired particle size and free Lead content ensured through proper operating parameters of plant.
Particle size checked by a test called as Apparent Density test (AD). Standard value for AD is 13~16 gm/cubic inch. Apparent density is inversely proportional to particle size.
Amount free lead and lead oxide is checked by Oxide Density (OD) test. Standard value for OD is 72~78% oxide or 22 ~28% free lead.
a) Rotating (drum): It is closed cylindrical drum, made of steel. The process of colliding lumps/cylinders with itself and wall of drum, and reaction with oxygen occurs inside this closed drum.
b) Transmission group: The rotation of the drum is done by means of a reduction gear group, which transmits the motion to the pinion and crown, which is connected to the rotating drum. Transmission system is driven by main motor through multi-belt and pulley.
c) Lubricating system: The centralized lubricating system, which supports all moving parts, the main motor and transmission system .The pinion and crown lubricating system is done automatically by means of a specific pump, which greases the kinematics motion following the time set in the PLC of the machine.
d) Cooling system: The Mill inside temperature is adjusted by means of an outside water circulation and by airflow, sucked by a fan positioned on the hood. The temperature adjusting is assured by thermocouple that gives the temperature value and by means of the PLC, which starts the cooling system if necessary.
e) Protection hood: In stainless steel assures a suitable protection to the moving parts and enables to collect the cooling water sprayed on the outside part.
f) Weight and Temperature controlling system: Three temperature probes fixed at three different locations inside the body of drum. Mill has a weighing device under the main mill, which indicates the weight of powder /oxide inside the mill .The feeding lead lumps amount depends on this weight.
Pulsaire Collectors/Filters
Lead oxide is harvested through a classifier high efficiency cyclone, bag-house filtration unit or Pulsaire collector and induction draft fan arrangement. Fine particles of powder enter into Pulsaire Collector /filter unit. These particles are then filtered through the vacuum cylinders/filter bags leaving its fine particles deposited on their outer surface. Meanwhile, the high-pressure air pulses effectively dislodge the deposit of these fine particles from the filter bag's surface and cause it to fall to the collecting hopper. The collecting hopper is connected with conveying system, which transfers oxide powder to oxide storage silos.
Conveying System & Oxide Storage Silos
The lead oxide powder is transfer to oxide storage silos by using multi-type conveying system, which is combination of snake conveyor, screw type conveyor and bucket elevator. The system is designed for smooth transfer of powder without leakage of dust in surrounding or working environment.
Snake Chain Conveyor conveys oxide through carrying blades attached to two strand special chains in an enclosed casing. Oxide conveyed between carrying blades, which make independent chambers without being stirred up.
There are three oxide storage silos of capacity 40 ton each. The digital weighing meter/indicator on silos shows the quantity of oxide present in silo.
LEAD OXIDE MAKING PROCESS
Lead oxide is (Pbo/Pbo2) is used in lead acid storage batteries as active mass. There are three lead oxide plants in ABL. The total production capacity oxide is about 25 ton daily/24hrs. The lead oxide making plant comprises of four main units
· Lumps making and storage silos
· Oxide mill
· Pulsaire collector/filter unit
· Conveying system and storage silos
Lumps casting/making:
Imported refined lead 99.97% is first melted down in furnace at about 320C. Then molten lead is sent through a pre-heated tube into the cylinder crown cavities by a centrifugal pump .
The lead quantity is adjustable by opening/closing the lead plug cock/adjusting screw or adjusting the machine rotation speed. The cam near the cylinders unloading pushes up the extractors and ejects the lead cylinders /lumps into a chute leading to buckets elevator, which feeds the cylinders /lumps storage silo. The cooling system solidifies the melting lead before the ejection enabling the transport by means of bucket elevator, to the cylinder silos.
Lead Oxide Mill Process
Lumps from storage silo, automatically fed into oxide mill. In the ball mill, Lead is converted to Lead Oxide, by grinding and oxidation process, which is an exothermic process. In this process, heat is generated and temperature of oxide is increased, to control the temperature with in the operating range of 115 to 135C, the ball mill temperature is controlled with constant flow of air and with the water spraying system controlled through solenoid valve. The fine particles of lead oxide remaining in the air stream are drawn out of the Ball Mill and conveyed into the Pulsaire Collector
Pulsaire Collectors/Filters (Operation and purpose):
The purpose of Pulsaire/filter unit comprises of following two factors.
1. The first one is to keep under vacuum all the system (mill) and not to have any dust emission on the working environment
2. The second one is to extract the lead oxide powder from the rotating chamber (where grinding and oxidation of the metal are done simultaneously) and bring it to the hopper of the cyclone filter from where it is mechanically sent to the oxide silos by conveyors.
The desired particle size and free Lead content ensured through proper operating parameters of plant.
Particle size checked by a test called as Apparent Density test (AD). Standard value for AD is 13~16 gm/cubic inch. Apparent density is inversely proportional to particle size.
Amount free lead and lead oxide is checked by Oxide Density (OD) test. Standard value for OD is 72~78% oxide or 22 ~28% free lead.