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Carbon blacks - rubber chemicals / Other industries

"Benefit from our experience with carbon blacks"

Refractory linings Foundry aids Ceramics Carbon brushes Plastic

 

Metal carbides: Rough shell – hard core

Numerous industrial applications call for a display of hardness. Examples can be found when metal plates are cut, when grinding surfaces, in the exploration and exploitation of natural gas and petroleum fields or when accurate holes have to be drilled in walls.

Components that have been rendered resistant to chemicals, heat or wear are also needed in other critical applications, such as for sandblasting jets, friction linings, burner nozzles, heat exchangers, etc.


All of these cases require tools and materials with a metal carbide armour-plating. Metal carbides exhibit maximum degrees of hardness and very high melting points and are able to withstand extreme chemical and thermal loads. Technically important metal carbides are manufactured from (semi)metals like boron (B), silicon (Si), tungsten (W), chromium (Cr), tantalum (Ta), niobium (Nb) or their oxides and a carbon source, which can be included in a carburizing reaction under protective gas or vacuum. Examples include:

 


As elements such as calcium, magnesium and sulphur “disrupt” the metal carbide lattice even in trace concentrations, thus lowering the stability of the carbide materials when in use, it is necessary to avoid foreign elements being dragged into the manufacturing process as far as possible.


Our LUVOMAXX Thermal blacks make suitable carbon sources with a high degree of purity. They originate from a manufacturing process that takes full account of the stated requirements of minimum trace element contents due to the high purity of the raw material.

 


Refractory linings

Things are hotting up in the steel industry: the production of pig iron and its subsequent processing into special steels demand process temperatures of 1200 to 1800°C. There are correspondingly high requirements to give the production equipment the best possible protection against thermal, mechanical and chemical factors. Here carbon-containing magnesia bricks are superior to other materials due to their high-melting-point components periclase (MgO) and C; they act as a working lining, e.g. in basic oxygen converters, arc furnaces, steel casting ladles or converter openings.

Carbon-containing magnesite bricks are manufactured by homogenizing suitable magnesite qualities (caustic magnesite, sintered magnesite) with cokable binding agents such as pitch or synthetic resins, followed by processes for shaping, tempering and vacuum pitch impregnation.

The carbon content of the bricks is also controlled by the addition of carbon blacks. The importance of the carbon content is that it reduces wear in the brick. LUVOMAXX thermal blacks are particularly able to ensure optimum reduction of the infiltration depth for molten iron and oxidic infiltrates into the pores of the rock due to their matching primary particle structure and high carbon density. Furthermore, as a carbon source (= internal reducing agent) they make an important contribution to the redox stability of the brick and as a binding agent to its erosion resistance.

 




Foundry aids

Walled up in the earth so steady
Burned from clay, the mould doth stand.
This day must the Bell be ready!
Fresh, O workmen, be at hand!
From the heated brow
Sweat must freely flow,
That the work may praise the Master,
Though the blessing comes from higher.
Take the wood from trunk of spruce tree,
Yet quite dry let it abide,
That the flame compressed so tightly
Strike the gullet deep inside!
Cook the copper brew,
Quick the tin in, too!
That the glutinous bell-metal
Flowing rightly then will settle!
Good! now be the cast beginning,
Finely jagged is the breach.
Yet before it start to running,
Let us pious verses preach.
Make the tap eject!
God our house protect!
Smoking in the handle's hollow
Shoots with fire-brownéd billow.
 
(Schiller: The Song of the Bell)
   


What Schiller could hardly have foreseen at the time is that a variety of modern processing aids are needed for molten metals to be cast and moulded reproducibly. Casting powder, mould release agents and metallic covering agents are responsible for the thermal insulation of the molten metal surface and influence the flow characteristics of the metal. They also prevent reoxidation of the metal, absorb inclusions and are responsible for lubrication between casting strand and mould (gravity die).



Carbon blacks, to be precise LUVOMAXX - lampblacks, are also used in this range of high-temperature applications. Due to their special properties, such as appropriate primary particle size, heat insulation capacity and high carbon density, they increase the stability of the casting powder, take part in thermal insulation and act as a carbon source for the reduction of metal oxides.
 




Ceramics: with LUVOMAXX we bring them to white heat

Oxide ceramic materials and metal carbide ceramic composites (cermets) are widely used as temperature-resistant materials in burner technology, furnace construction and pyrometry. Here carbon blacks as involved in the manufacture of SiC as an ultra pure carbon source. As the relatively coarse-particle, structureless thermal black has good heat insulation properties, it is also used as an insulating constructional element in high-temperature ceramics.






Carbon black lubricates…”

This is not only something that experienced barbecue experts discover when cleaning their grill equipment. Carbon black can also be found in the electric motors that are all around us today in automobiles, household appliances and model railways, helping the carbon brushes to perform their task. Adding LUVOMAXX lampblacks ensure that the carbon brushes remain free moving and the pressure on the collector electrode is always correct.
 



Plastics applications: Black is beautiful…

Whether for finished goods or recyclates: a hint of LUVOMAXX carbon black acts as a convenient to use pigment for determining the coloration of plastic articles, provided of course that the required shade (loosely based on Henry Ford) lies between light grey and deep black.

Special LUVOMAXX carbon black types LUVOMAXX MPC, LUVOMAXX N-990 comply with the relevant European and US requirements and are a permitted pigment additive for articles in contact with foodstuffs.

In addition, due to their UV absorption characteristics, our “black jewels” provide efficient aging protection for plastics exposed to light.