Scotland's Brick and Tile Manufacturing Industry

(see bottom of article for a further link)

Nettle – Firebricks

Within recent years the need has become very urgent for a high-grade firebrick containing more than the usual 35 – 40 % alumina. In our Nettle brand, we possess an excellent example of this type of brick.

Nettle is now made exclusively at our Manuel Works which are constructed on the most up-to-date lines embodying all the best developments and technique known to the refractories industry. The alumina content is 43 – 44, while the amount of pernicious alkali fluxes is unusually low. As a result of this and of the thorough burning it receives in the kiln, Nettle is highly refractory and offers excellent resistance to the destructive influence of slags. The after contraction is extremely low and marked constancy of volume is displayed even after exposure to long soaking heats.

For general high-temperature work involving heavy-duty, Nettle is unrivalled.

Thistle – Firebricks

Thistle is manufactured at our Castlecary Works from high-grade raw material.  Since it was placed on the market many years ago, Thistle has steadily built up a reputation for high quality and had proved itself to be very economical for general furnace construction. Possessing good mechanical strength and toughness. Thistle offers high resistance to abrasive action. It is moderately high in Alumina, containing 37 – 38 %, while the alkali is very low. As a result of complete burning during manufacture, Thistle shows only a very small after contraction.

Stein Glasgow – Firebricks

Stein Glasgow brand is a first-grade firebrick, containing 34 – 36 % alumina. This brand is suitable for general furnace construction and displays excellent resistance to spalling, corrosion and abrasion. It has good load-bearing characteristics under reducing conditions. This bricks is especially suitable for the in-wall and top of blast furnaces and also for hot blast stoves. It successfully resists disintegration from the action of carbon monoxide at low temperatures.

Stein – Firebricks

Stein brand is a dense, tough firebrick of uniform texture and contains 33 – 35 % alumina. Like Thistle, Stein possesses and excellent service record in all types of applications. It displays very good resistance in particular to ferruginous slags and to reducing conditions. Stein is very suitable for positions where good resistance to abrasion is necessary.

Stein Ladle – Firebricks

The chief requirements of a good ladle brick are:-

1. Toughness to resist corrosion and abrasion by liquid steel and slag.

2. Suitable chemical composition to resist the energetic action of slag.

3. Excellent shape and size so that the joints are kept as thin as possible

Stein Ladle brand fulfils all those requirements and gives unsurpassed service. It is an economic, dependable and durable product made under carefully standardised conditions.

J G S & Co  – Semi Silica Bricks

This material has been developed particularly for use in positions where silica would be too sensitive to spalling and where normal firebricks would show excessive vitrification and deformation under load. JGS & CO contains 84 – 86 % silica and is of good refractoriness. Its ability to withstand dry soaking heats without showing contraction makes it especially useful for soaking pit walls, heating furnaces and boiler arches. It also stands up well under load, even under reducing conditions.

Bluebell – Silica Bricks

Bluebell is a straight silica brick containing 95 % silica. The valuable properties of this material may be summarised as follows:-

1. High fusion point.

2. Excellent strength and rigidity retained almost to the fusion point.

3. No dangerous volume changes at working temperatures ( a result of thorough burning giving complete conversions of the quartz)

The manufacture is carefully carried out so that accurate shape and size are obtained. It is on the combination of these properties that Bluebell’s excellent record is based.

Daisy – Silica Bricks

It has been long recognised that all tridymite brick would possess certain desirable features which are not obtained in the ordinary silica brick. The thermal expansion would be lower and because of this, the tendency to spall would be reduced. Due to complete re-crystallisation to tridymite, the mechanical strength and under load characteristics would also be much improved. Daisy brand contains 94 – 95 % silica and in this material, we have succeeded in producing a brick with over 90% of the crystalline silica in the form of tridymite.

Special Refractories – 

Super refractories of the high alumina type have become very necessary in recent years through increasingly severe conditions being imposed on industrial furnaces. The limits to which a furnace can be driven are determined by the ability of the refractory lining to withstand the severe conditions. In some processes, these conditions are too severe for firebricks even of the highest quality and high alumina refractories are necessary. Normally they need only be used in the more exposed parts of the furnace.

In the silica-alumina series, the refractoriness and resistance to basic metallic fluxes increase rapidly with increase of alumina content. A firebrick consists essentially of mullite (3 AL2O3  2SI02 )and silica, cemented together by the siliceous glass. The amount of mullite formation in a brick increases directly with the alumina content ( up to 72 % AL2O3 ), provided the bricks are thoroughly burned in the course of manufacture. The excellent properties of high alumina materials are due to their large mullite content. Briefly, these are

1. High refractoriness

2. Excellent resistance to basic slags at working temperatures.

3. Excellent load-bearing properties which are retained at elevated temperatures.

4. Constancy of volume.

5. High conductivity – four or five times greater than that of a firebrick.

The chief source of these special high alumina refractories are sillimanite, cyanite, andalusite, bauxite, diaspore and corundum. The cost of these raw materials and also the cost of manufacturing is higher than the corresponding costs of ordinary bricks.

We should be glad to supply fuller information concerning or range on request. The brands are

Stein 63                  63 % alumina

Stein 73                  73 % alumina

Stein Sillimanite

We also supply suitable refractory cements for laying each brand.

The principal uses may be summarised as follows:-

1. Slag lines in metal furnaces.

2. Muffle furnace walls and combustion chambers

3. Rotary cement kiln linings.

4. Limekiln linings.

5. Positions exposed to severe attack by iron oxide or alkalies and where high strength is required.

6. Positions involving excessively high temperatures where intermittent working forbids the use of silica.

Alcro

Alcro is a high-grade chrome alumina brick, the main feature of which is its high resistance to the corrosive and abrasive action of iron-rich slags.

Its chief applications are:-

1. Clinker line of boiler furnaces

2. Soaking and reheating furnace bottoms

Glass tank blocks

The manufacture of high-class tank blocks demands special care at all stages of the process. Careful selection of the raw clay, expert workmanship in the making and thoroughness of burn, all ensure a constant high standard of quality. The chemical composition and physical structure of our blocks result in their displaying a strong resistance to the destructive influences of molten glass, alkalies etc. The blocks wear very evenly, do not honeycomb and consequently, there is no tendency to produce stones in the glass. All blocks are ground after burning on the jointing faces to accurate size so that tight joints may be obtained.

Special shapes

We also supply special blocks and machine feeder parts of accurate shape and size and designed to resist thermal shock.

Further details on the brick composition and use can be obtained from the following document.

Refractories for iron & steel works, blast furnaces & coke ovens – John G Stein & Co Ltd