• Hammer mill and hammer crusher
    Hammer Crusher/Hammer Mill

    Hammer Crusher/Hammer Mill

    Function
    Pre-crushing and crushing operation of exhausted lead acid batteries, in order to facilitate the subsequent processing and the separation of the various components including sulphuric acid drainage and possible recovery.

    STC hammer mill/crusher is composed of the following main parts:

    • Feeding and discharging hoppers;
    • Hydraulic opening;
    • Crushing chamber with anti-wearing armours;
    • Rotor with strong shaft supported by self alingning bearings;
    • Flying hammers;
    • Adjustable grate;
    • Equipment support frame with anti-vibration system to avoid stress and vibrations;
    • Lubrication system;
    • Different drive unit with flywheel, belts and pulleys, flexible coupling, hydraulic coupling, softstarter.

    The construction is made in strong acid-resistant stainless steel.

    HAMMER MILL
    Model Average  Production t/h* Installed Power kW Weight kg Nr. of hammers
    HM900 05-8 75 7.000 22
    HM1200 8-15 110 9.000 28
    HM1500 15-25 132 12.000 36

    *Nominal average capacity: the equipment can accept peaks up to 50% of nominal capacity for short periods.

    Higher capacity available through bigger equipment or combination between pre-crusher (shredder or STC hammerl mill without grate) and Hammer Mill.

  • Filter press
    Filter press

    Function

    Separation and removal of solid particles from a liquid by means of squeezing process.

    The filter press is a semi-continuous machine, equipped with a certain number of filtering elements able to remove the solid particles contained in liquids or sludge of various nature.

    The main components are:

    • The structural support of the filter which includes:
      • Fixed head with inlet and outlet manifolds;
      • Fixed head with supporting structure of the hydraulic system;
      • Lateral or high beams for rigid connection among heads and for filtering plates;
      • Support;
      • Mobile head, sliding on rolls, over the sliding beams.
    • Filtering pack which includes all the elements involved in the solid-liquid separation process:
      • Filter plates;
      • Membrane Plates made of PPH/EPDM;
      • Filter cloths made in multi wire polypropylene.
    • Movable system for liquids collection composed of:
      • Liquids collection panels in stainless steel;
      • Hydraulic actuators for panel motion.
    • Main hydraulic system consisting of a main hydraulic cylinder and a hydraulic station:Feeding and discharging hoppers;
      • Cylinder diameter: working pressure of 250 bar;
      • Hydraulic control unit composed of a three-stage pump activated by an electric motor with differential pressure control valve.
    • Membranes water-squeezing skid (serving two filter-presses) composed of:
      • Multistage centrifugal pump;
      • Water tank;
      • Piping and instrument system.

    The machine is equipped with an automatic opening system that enables the progressive discharge of the solid cake collected between the filtering plates.

    Can be equipped with automatic cloths washing system.

    Cake water washing and cake air blowing are optional features always present when filtering lead paste and in other mining /environmental application.

    STC FILTERPRESS plates number and size are selected according to the process and range from 500x500 up to 1500x1500 mm with chamber volume up to 5000 dm3.

    Safety barriers and enclosure are part of the STC supply.

  • Rotary screen
    Rotary screen

    Function
    The rotating screen enables the washing and separation of the crushed batteries components through size classification.

    Typical applications include:

    • Lead paste separation from other components (metallic lead grids and plastics);
    • Separation of metallic lead into different fractions (fine metallic grids and coarse connectors/poles);
    • Dewatering and cleaning of plastic components (Polypropylene and Heavy plastics).

    Depending on the application, the rotary screen may have different shapes (cilindrical, exagonal, octagonal) and different screening mesh (from 0,5 mm up to 50 mm).

    Driving unit can be equipped with direct coupling, belt and pulleys or rack and chain and all with adjustable speed through inverters.

    Rotary screens are provided with protective guards, hood/enclosures, inspection doors, flanged nozzles for fumes suction, anti-vibrating system, internal washing sprayers, external cleaning system with high pressure water.

    The rotary screens are available in any size.

  • Delta separator
    Delta separator

    Function
    Separation of the lead paste into two different fractions: coarse and fine lead paste to facilitate the operation of the desulphurization equipment.

    The equipment is based on the elutriation principle so that the fine lead paste particles are transported with a small stream of recycled water in opposite direction of sedimentation thus achieving the classification and sorting between fine and coarse fraction due to their different sedimentation velocities.

    Fine lead paste suspension is collected from the top while the coarse fraction is collected through the lower screw conveyor.

    The use of this innovative and very unique STC equipment for lead paste is highly recommended because this separation allows the simplification of all the downstream equipment avoiding the problems of fast settling and the possible clogging of pipes, pumps, tanks and leading to the reduction of energy consumption of the related equipment.

  • Automatic charge preparation and furnace feeding system
    furnace feeding system

    Function

    Paste, metallic lead and recycles (dross, flue dust etc.) from battery recycling need to be premixed with fluxes (Fe, Na, C etc.) before being fed to the furnace. STC designs and supplies automatic systems for charge preparation where the various products and reagents are stored in hoppers with extraction and dosing system and automatic control of the weight of each ingredient according to the metallurgical recipe.

    STC has implemented a paste pelletizing system where the paste after filter press is premixed with Soda Ash and Carbon and extruded in form of pellets. The main advantages are in the reduced amount of fluxes used, in reduced dust load in the baghouse, in the possibility to avoid the paste storage on the ground resulting in a cleaner indoor environment.

    When the charge is prepared, it is fed to the furnace through an automatic vibrating feeder travelling on rail, embedded into the floor, thanks to a motorized wheel system. The capacity of the hopper and the feeding rate is selected according to the furnace capacity. In case of multiple furnace one feeding machine can serve two parallel rotary furnaces.

    Depending on the layout, the hopper of the automatic furnace feeding system can be fed directly by means of a belt conveyor, with payloader or with automatic loading boxes.

    Alternatively, the rotary furnace can be fed through loading spoons to be fixed to the forklift rotating device but this solution is recommended only for small furnace capacity.

  • Rotary furnaces
    Rotary Furnace

    Function

    To be used for all kind of lead products, the Rotary Furnaces today are the most used smelting furnaces in secondary lead production due to its flexibility and low operational costs.

    STC designs and supplies Rotary Furnaces in several sizes from 750 up to 12.000 lt of molten lead with single or double fumes passage.

    The furnace rotation can be achieved by simple riding rings rotating on motorized and idle wheels or by rack and pinion.

    A VFD allows speed adjustments. The feeding door is fully automatic operated with pneumatic cylinder or gearmotors. Slag and lead can be poured either from front or central nozzles. Refractory is made of Chrome-Magnesite bricks. Burner type can be oxy-fuel or standard air-fuel where fuel is natural gas, LPG, combustible oil.

    Standard STC’ Rotary Furnace
    Furnace capacity
    (useful molten bath) litres
    Charge capacity
    (t of paste/batch)
    (+/- 15%)
    Diameter (mm) Burner power
    Kw
    750 6 2000 750
    1500 8 2500 1000
    3000 13 3000 1750
    6000 24 3250 2500
    9000 32 3500 3500
    12000 40 4000 4750


    Extraction fumes tower with suction control valve and complete canopy are essential part of the RF design. In Tilting configuration, the furnace is mounted on a strong steel frame with lifting hydraulic cylinders. Slags and lead can be removed in different ways: both from the feeding door (slag stopper is provided) or alternatively from dedicated spout for lead tapping while the slags are quickly removed from furnace mouth by tilting the furnace until it is empty. Trolleys and ladles for lead and slag tapping are provided. Depending on the layout, a receiving kettle next to the furnace can be installed in order to perform a first dross removal prior to pump the molten lead to the refining kettles. Post combustion chamber can be provided for VOC and CO control. Complete Air Pollution Control line designed to meet the stricter regulations is available.

  • Melting tilting rotary furnance
    Meltting tilting rotary furnace

    Function

    To be used for clean metallic lead fraction coming from STC breaking and separation plants, the TRF allows a quick melting operation at low temperature, with almost zero fluxants and with direct discharge of the molten lead into the refinery kettle. The same TRF is applicable to melt the metallic lead coming from non-STC battery breaking provided that the metallic fraction (normally presenting poor quality because of paste and plastics contamination) is previously processed in the STC Metallic Fraction Purification Unit.

    Burners

    STC furnace can be fitted with different kinds of burners:

    • Standard air-fuel burner;
    • Oxygen enriched air-fuel burner;
    • Pure oxygen-fuel burner

    As fuel natural gas, LPG and combustible oil are normally used. Depending on the furnace configuration the position of the burner can be either on the feeding door (single passage) or in the back of the furnace (double passage).
    Burner cooling system is provided when necessary.

    The gas ramp is in compliance with the local safety regulations and is controlled by PLC.

    It allows changes in ratio to adjust the oxidation/reduction phases according to the process needs.

  • Burners
    Burners

    STC furnace can be fitted with different kinds of burners:

    • Standard air-fuel burner
    • Oxygen enriched air-fuel burner
    • Pure oxygen-fuel burner

    As fuel natural gas, LPG and combustible oil are normally used. Depending on the furnace configuration the position of the burner can be either on the feeding door (single passage) or in the back of the furnace (double passage). Burner cooling system is provided when necessary. The gas ramp is in compliance with the local safety regulations and is controlled by PLC. It allows changes in ratio to adjust the oxidation/reduction phases according to the process needs.

  • Refining kettles
    Refining kettles

    To be used in Lead refining operations to produce the lead of proper quality as per customer’s specifications and market requirements (SOFT LEAD, ULTRA SOFT, LEAD ALLOYS).

    The operations are of two types:

    1) removal of unwanted metals like Antimony, Copper, Tin, Arsenic, Tellurium, Nickel etc. (Bismuth and Silver removal is possible but requires long procedure and special equipment);

    2) Addition of virgin metals or master alloys in order to reach the quality specified by Customers like Pb/Sb, Pb/Ca (Sn, Sb, Se, As, Ca/Al etc.).

    The refining operations are carried out in consecutive steps, transferring the molten lead from one kettle to the next one by means of pumps after completion of specific process treatment, working at different temperatures and adding specific chemicals and materials in the different refining phases (sawdust, sulphur/pyrite, O +air, NaOH, NH Cl, NaNO, Zn, Red-P). The number and size of kettles depend on production plan.

    STC standard kettles * 
    Capacity Ton Pb 10 20 30 50 70 100 120 150 180 200
    Pot diam. (mm) 1200 1400 1800 2200 2500 2750 2850 3000 3200 3600
    Burner power (kw) 250 400 550 700 900 2x550 2x700 2x800 2x900 2x1000


    * STC can produce any other size according to specific customer needs (e.g replace existing pot).

    Kettles system includes:

    • The Pot with elliptical or hemispherical bottom (depending on size) with double temperature control (internal and external);
    •  The external shell (oven) with combustion gas exit and refractory lining made with Al-Si bricks or ceramic fiber modules;
    • The heating burner for natural gas, LPG or combustible oil, with its gas ramp, and the “no-flame” function in order to achieve a cooling of the lead inside the pot;
    • The process fumes hood, openable and removable with support baseplate for pump, agitator and oxy-air lance Kettles installation depends on the layout and the Customer needs and it can be either completely above ground with a service platform or partially/completely underground. Construction material is carbon steel for the hoods and for the external shell while the pot is made of low carbon steel or stainless steel.
  • Dross/slag removal equipment
    Dross/slag removal equipment

    The purpose of the machine is to remove the skim/dross from the kettles surface during lead refining operation. Two different kinds of dross removal machines are available from STC: Skimming rotating paddles and Skimming rake.

    Skimming rotating paddles

    The dross is removed continuously through skimming paddles mounted on a chain system and immersed into the molten lead thus removing efficiently the dross from the surface of the molten lead.

    Dross is discharged into a receiving box/container for further reprocessing.

    The STC DROSS PADDLES SKIMMING MACHINE consists in the following main parts:

    • Driving unit;
    • Skimming paddles with chain;
    • Immersion adjustment system;
    • Supporting frame with lifting lugs;
    • Local electric panel

    The STC DROSS SKIMMING MACHINE is designed for any kettle size and can be adapted to existing kettles.

    Skimming rake

    The dross is removed continuously via skimming rake. Through a forward and backward movement, it efficiently removes the dross from the surface of molten lead, discharging them into a receiving box/container for further reprocessing.

    In its rear position, the skimming arm with its rake is lifted and advanced up to the front-end position. In this position, the skimming arm is lowered until the rake plunges into the dross/slag. The scraper is then withdrawn thereby removing the dross/slag, which via the extraction chute placed on the kettle, flows into the receiving box/container/ladle placed underneath. This operation is repeated until the dross/slag are completely removed from the hot metal surface.

    The STC DROSS RAKE SKIMMING MACHINE consists in the following main parts:

    • Driving unit with electro-pneumatic system;
    • Skimming rake mounted on strong arm;
    •  Extraction/resting chute for easy and continuous extraction of dross and for the reduction of the metallic lead entrapment;
    •  Supporting frame with lifting lugs;
    • Local electric panel

    It is always recommended to connect the dross receiving box/container to the existing suction system in order to reduce the possible emission of dust in the workplace.

    Both STC DROSS SKIMMING MACHINE are sturdy and designed for any kettle size and can be adapted to existing kettles and can be used with agitator in operation.

  • Softening oxylance

    STC OXY-AIR LANCE is used in lead refining operation for the selective oxidation of unwanted elements. After Cu removal, As, Sn and Sb are removed from the molten lead as they are oxidized before lead.

    The oxy-air lance is submerged into the molten lead and through flexible and protected pipes, connected to a local regulating panel (where pressure and flow rate of gases are controlled), it provides a jet injection of mixture gases (O2 and compressed air). Multiple oxy-lance arrangements are available for big kettles.

    The reaction is exothermic and therefore the temperature must be kept under control with kettle cooling system if necessary.

  • Lead ingot casting line
    Lead ingot casting line

    The STC Lead Ingot Casting Line (LIC) is used in the final Lead production process to transform the molten lead into solid ingots, in proper commercial size and organized in stacks fixed with plastic straps ready to be sold and delivered to final users. The shape and weight of final ingots is according to Client specifications (normally 25 or 40 kg). The Lead Ingot Casting Line is suitable for all kinds of lead: pure soft, Ultra Soft, Antimony alloys, Calcium/Aluminum alloys, Tin/Selenium alloys and remelted lead (unrefined).

    Advantages

    • No fumes or steam formation in working area;
    •  Automatic accurate lead dosing system;
    • Crack and dross (oxides) free high-quality ingots;
    •  Availability of automatic skimming with robot
    • Availability of fully automatic stack formation with robot (anthropomorphic or cartesian type);
    • Stack weighing, label printing and application;
    • Production data reporting and recording with remote access;
    • Regular shape of stacks;
    • Preassembled and tested line

    AVAILABLE CAPACITY: 5 -10 - 15 - 20 - 30 Ton/ hour of lead (referred to soft lead) INGOT WEIGHT: 25 – 45 kg each (different weight is available if requested)
    STACK COMPOSITION: five or six ingots per layer and up to 5-8 layers.

    Optional and system integration

    Depending on the Client needs, a wide number of optional features are available for STC lead Ingots Casting Lines:

    • Ingots surface homogenization burner (honing);
    • Automatic ingot skim removal by robot;
    • Automatic rejection of wrong/defective ingots;
    • Stack receiving conveyor including stack formation, stack weighing and x number of stack holding positions as per Client needs;
    • Manual or automatic strapping system (up to 4 straps per stack);
    •  Ingots automatic 2/3 colors marking system;
    • Stack labelling with indication of weight, lot number, date, batch number, alloy etc.;
    • Bar code or other identification code inkjet or laser printing on each ingot;
    • Stack doubler with a pick and place system to put one stack on another and reduce handling;
    • Water cooling system and circulating pumps;
    • Lead pumps.

     

  • Lead pumps
    Lead pumps

    Lead pumps are mainly used for two operations: transfer the molten lead from one kettle to another during refining operations and feed the lead casting line. The pumps produced by STC are centrifugal-vertical type, for immersion in the molten lead, with rotation speed and flowrate controlled and adjustable via VFD. Direct motor coupling or with belt and pulleys. Construction material is carbon steel, stainless steel, cast iron with heat treatment where necessary.

    STC STANDARD LEAD PUMPS 
    Flow t Pb/h 0÷10 10÷20 25÷50 100÷150 200÷300
    kW 3 5,5 7,5 11 18
  • Lead agitators
    Lead agitators

    Lead Agitators are used for molten lead stirring and blending operation. The pumps produced by STC are centrifugal vertical type, for immersion in the molten lead, with rotation speed and flowrate controlled and adjustable via VFD. Motor coupling with belt and pulleys. Construction material is carbon steel, stainless steel, cast iron with heat treatment where necessary. Propellers are available in different size/shape and fully interchangeable.

    STC STANDARD AGITATOR
    Pot size Ton 10÷20 30÷50 70÷100 120÷150 180÷200
    kW 11 30 37 45 55
  • Paste pelletizer
    Paste pelletizer

    STC has implemented a paste pelletizing system where the paste after filter press is premixed with Soda Ash and Carbon and extruded in form of pellets. The main advantages are in the reduced amount of fluxes used, in reduced dust load in the baghouse, in the possibility to avoid the paste storage on the ground resulting in a cleaner indoor environment.

  • Scrubbers
    Scrubbers

    STC designs and supplies a full range of equipment, services and engineering solutions for the Air Pollution Control, applicable in many industrial sectors like production, non-ferrous metal, food processing, chemical and petrochemical, waste and waste water and many others. STC wet scrubbers are available in many configurations: horizontal, vertical tower, single, double or triple stages, venturi scrubber, fixed bed, floating bed. The working principle is based on the absorption of the pollutants in water where the air emission is counter-washed by a water recirculating system through spraying nozzles.

    The scrubbers are partially filled with packing media (static bed or floating bed are available) made of proper material (Rashing rings, saddle, balls, Pall rings, Tellerette, or similar) to facilitate the absorption reaction by increasing the contact surface between the washing water and the contaminated gas.

    Depending on the application, different sorbents can be added (also in combination using two- or three-stages scrubber) to the circulating water to facilitate the absorption of the unwanted substances: Lime, Caustic Soda, Sulphuric Acid, Hydrogen Peroxide, Ozone and other chemicals are used to specifically target certain compounds. A final demister will remove the mist and any drop of water from the emission.

    • Application in many industrial sectors for the abatement of particulate and hydro-soluble;
    • substances like H2SO4, H2S, HCN, HF, SO2, HCl, NH3, Odours and other toxic components.;
    • Removal efficiency up to 99%;
    • Flowrate from 5.000 up to 100.000 Nmc/h (higher capacity available upon request);
    • Construction made in PP, PVC, HDPE, FRP and AISI 304/316 Piping, instrumentation and electric local panel with PLC to control the process are included as well as fan, ductworks, dampeners, stack, chemical dosing system, supporting structures and service platforms. The design parameters meet the strictest environmental regulation.
  • Baghouse filters
    Baghouse filters

    STC designs and supplies a full range of equipment, services and engineering solutions for the Air Pollution Control applicable in many industrial sectors like battery manufacturing, battery recycling, lead production, non-ferrous metal, food processing, chemical and petrochemical, waste and wastewater and many others.

    Pulse jet baghouse

    STC modular Pulse-Jet Baghouse is designed and manufactured for the removal of dust and particulate matter from process fumes in any kind of industry and especially in the non-ferrous metal production (Lead, Aluminium, Copper, Brass, Zinc).

    Advantages

    The main advantages of STC pulse jet baghouse can be summarized as follows:

    • High separation efficiency;
    • Very low residual dust emission <0,5 mg/Nm meeting the strictest emission limits;
    •  High abrasion and chemical resistance;
    •  Capability to filter even the finest dust particles (PM 10 – 5 – 2,5);
    •  Easy cleaning by sector and independently from filtering operation • Low pressure loss;
    •  No dust penetration into the carrier material;
    • Long service life;
    •  Pre-coating system;
    • Fast and simple bag replacement;
    • Flow rate from 10.000 up to 200.000 Nmc/h;
    •  Operative temperature up to 260°C

    In secondary lead production, the combination with STC post combustion chamber, HEPA filter and STC scrubber will allow to reach an emission level closed to zero. Depending on the application, some optional configurations are available:

    • Walk-in plenum;
    • Thermal insulation;
    • Flue dust collection and transportation system for recycling/disposal;
    •  Fire protection or explosion suppression equipment where required;
    •  Final section with HEPA filter ;
    • Chemicals preparation/dosing system (e.g. Bicar, lime, activated carbon) into a dry absorber;
    • Chamber with flue dust recycling

    Typical auxiliary equipment and services may include the following: Piping, instrumentation, electric local panel with PLC to control the process, fans, ductworks, dampeners, stack, chemical dosing system, supporting structures and service platforms. STC Pulse jet baghouse is complete with:

    Housing

    Modular construction made with panels (bolted/welded) available in different material (galvanized steel, Corten A, stainless steel) designed for appropriate negative pressure. Depending on site environmental conditions and process parameters, it can be fully insulated and heated.

    Retainers

    Available in galvanized steel or stainless steel AISI 304/316.

    Filter Bags

    Variable diameters available and different lengths available from 2.5 up to 5 m, bags material selected depending on application (Polypropylene PP, Polyamide PA, Polyacrylonitrile PAN, Nomex, Polyester PES, Polytetrafluorethylen PTFE, Fiberglass FRP).

    Air jet cleaning system

    An air manifold distribution and solenoid valves system provides an effective cleaning through a short burst of compressed air injected in each bag through a special venturi nozzle for short time (usually 0,1-0,3 seconds in sequences controlled by an electronic sequential timer).

    Storage/collection Hopper

    Pyramidal hopper with 60-degree minimum side slope with inspection door, for collection and storage of the removed dust.

    Hopper Screw Conveyors

    Each hopper is provided with a screw conveyor to convey collected dust to the discharge point where a rotary valve is installed.

    Walk-in plenum

    For outdoor installation, the upper part of the filter module can be provided with a walk-in outlet plenum which allows maintenance in case of bad weather.

    Inlet/Outlet Dampers

    Each module is equipped with an inlet/outlet butterfly damper (manual or actuated) to be used for maintenance purpose.

    Inlet /outlet Manifold

    Manifold to distribute/collect the air to/from each module.

    Supports & access platform

    Structural support steel frame for local wind or seismic events, static and dynamic equipment as applicable shall be provided as well as a maintenance & inspection service platforms.

    Instrumentation

    The following instrumentation is normally provided: differential pressure transmitters (complete system and individual modules), leak detection system, temperature transmitters, hopper level probes, dampers limit switches, speed switches.