We supply a range of grades of a specially produced oxide.

As inorganic products they show one great advantage over natural materials used for polishing. That being the constancy of their physical and chemical properties no matter at what temperature or under what pressure they are used.

The aluminium oxide is in the form of agglomerates that consist of numerous primary crystals. The size of these crystals depends on the degree of calcination. Generally the higher the calcination temperature the larger the primary crystals.

Grades with larger crystals can be used for grinding and lapping while smaller crystals lend themselves to equalizing and smoothing the surfaces on which they are being used without removing great amounts of material. On car and aircraft bodies for example.

The primary crystals of the aluminas are extremely hard. They rank at 9 on the Mohs scale alongside corundum, and one level below diamond.



Products

  • P15, LK and L alumina products
    Aluminium silicate and calcined alumina products for automotive paint renovation through to final polishing, soft metals, plastics and a range of other surfaces

      P15, L and LK SERIES

      Polishing Grades

      GRADE POLISH CUT OIL ABS % SURFACE m2 / gm TYPE SPEC MSDS
      P 15
      Bodyshop finishing, showroom, soft plastics, perspex, 8/9% dosage
      10 <1 100 12 - 17 Aluminium silicate PDF PDF
      L 10
      Soft metals, plastics, paint polishing
      10 1 45 - 60 4 - 11 Calcined alumina PDF PDF
      LK 5
      Soft finishing polish
      10 2 23 - 36 10 - 17 Calcined alumina PDF PDF
      L 02
      Scratch removal and polish
      9 2 36 - 45 10 - 18 Calcined alumina PDF PDF
      LK 9
      Old paint renovation
      9 2 28 - 40 10 - 18 Calcined alumina PDF PDF
      LK 6
      Good all-round product, scratch removal, old paint renovation
      9 2 25 - 40 10 - 17 Calcined alumina PDF PDF
      LK 15
      Good all-round product, scratch removal, old paint renovation
      9 2 30 - 41 9 - 17 Calcined alumina PDF PDF
      L 01
      High end polish, some scratch removal
      9 2 42 - 50 10 - 17 Calcined alumina PDF PDF
      LK 35
      High cutting compounds
      8 3 32 - 47 9 - 17 Calcined alumina PDF PDF
  • LZ alumina products
    High alpha alumina products for cutting, buffing and no smear hologram free polishing

      LZ SERIES

      Cut and polish values not given as these are blend products designed to be used with others that will also influence performance. Max recommended inclusion level for all products 12%. Alpha alumina contents 99.4 - 99.6%.


      NOTE: You will see that most of the LZ specifications are very similar, and in some cases exactly the same, as often the only difference between them is furnace residency time and one or two other minor factors that will produce a difference in performance

      GRADE OIL ABS % SURFACE m2 / gm TYPE SPEC MSDS
      LZ 1
      High alpha al, no smear, hologram free
      50 - 65 15 - 20 Alumina PDF PDF
      LZ 2
      High alpha al, no smear, hologram free, for buffing
      55 - 70 14 - 19 Alumina PDF PDF
      LZN 1
      High alpha al, no smear, hologram free
      50 - 65 15 - 20 Alumina PDF PDF
      LZN 2
      High alpha al, no smear, hologram free
      50 - 65 15 - 20 Alumina PDF PDF
      LZA 21
      High alpha al, no smear, for cutting
      65 - 83 4 - 6 Alumina PDF PDF
      LZA 22
      High alpha al, no smear, for cutting
      49 - 66 3.5 - 5.5 Alumina PDF PDF
      LZA 23
      High alpha al, no smear, for cutting
      54 - 68 5 - 7 Alumina PDF PDF
      LZ 3A
      High alpha al, no smear, hologram free, for buffing
      >95 25 Alumina PDF PDF
      LZ2 AL
      High alpha al, no smear, hologram free, as LZ 2 but for rotary application
      55 - 70 14 - 19 Alumina PDF PDF
      LZ2 PL
      High alpha al, no smear, hologram free, as LZ 2 but for extender application
      55 - 70 14 - 19 Alumina PDF PDF
  • B and CDM alumina products
    Ultrafine alpha alumina, hologram free product

      B SERIES

      Ultrafine high end polishing products 99% below 1 micron

      GRADE OIL ABS % SURFACE m2 / gm TYPE SPEC MSDS
      BR 1
      Alpha alumina, hologram free
      50 - 85 4 - 6 Calcined alumina PDF PDF
      BS 1
      Tetra / Kappa alumina, hologram free
      55 - 90 15 - 19 Calcined alumina PDF PDF

      CDM SERIES

      Ultra fine high end alpha alumina products

      GRADE CRYSTAL SIZE mm TYPE SPEC MSDS
      CDM 10
      Alpha alumina, hologram free, 12% max addition
      50 Calcined alumina PDF PDF
      CDM 10B
      Alpha alumina, hologram free, 12% max addition
      10 - 160 Calcined alumina PDF PDF



Further Information

Polishing aluminas are used in many processes and applications.
Precision lapping, final lapping, hydro abrasion, and polishing.

The benefits of calcined alumina are

- crushing properties of  the agglomerates and primary crystals
- hardness of the primary crystals
- grain shape on both damaged and undamaged crystals
- high melting point.
- resistance to thermal shock
- oil absorbtion
- workability
- the purity of the powder

The balance of cutting and abrasion are the markers by which the decision on the most suitable grade for any application is made.

- Cutting effect is measured on a scale of 1 to 10. 1 represents a very low cut, whereas 10 represents a high degree of abrasion.

- Polishing effect works in a similar way. A level of 1 giving a highly reflective finish, whereas level 10 would give a lustrous finish.

Calcined alumina can be used alone, or in a combination with other materials in a compound.
Compound binders usually involve the use of an oil or wax. The ratio of liquid/paste to solid content is generally around 50/50 or thereabouts.

Method of delivery

- In a suspension with oil, water, or other chemicals
- Without additives
- As a paste
- Mixed with emulsions
- blended into the matrix of a solid polishing bar

The above can be applied manually, or in automated processes in car plant production lines, airless processes and other.

Other applications

- Brake linings
- Household cleaners
- Car cleaners
- Car polishes
- Stone polishes
- Vibro finishing

The Bayer process

In the late 19th Century the search was on to find a mordant, or fixer for textile dyes. In fact what was found was to revolutionize not only the metal industry, but several others too, including surface treatment.

In Russia Carl Josef Bayer discovered that aluminium hydroxide that precipitated from his alkaline solutions was crystalline in  form and so could be easily filtered and washed, as opposed that which precipitated from an acidic solution which was gelatinous, and so difficult to handle. The year was 1887.

Bauxite, in its raw form, contains only 30 – 50% aluminium oxide, the rest being in various proportions, titanium dioxide, silica and a variety of iron oxides. The aluminium oxide must therefore be refined/concentrated before it can be processed into either aluminium metal or the alumina powders used in polishing, refractory, ceramic  and other applications.

Initially the raw bauxite is washed in a solution of Sodium hydroxide at 175 degrees centigrade. The aluminium oxide in the bauxite thus becomes Sodium aluminate.

As the impurities in the bauxite do not dissolve they can be easily filtered off. The resulting red mud is highly toxic (Reference the Ajka Alumina plant disaster in 2010 when huge quantities of red mud were discharged into the Danube).

Next the alkaline solution is cooled and aluminium hydroxide precipitates out. This precipitant is then calcined and hydroxide decomposes to oxide giving off water in the process.

Thereafter there is a divergence as the alumina to be used for aluminium metal production, and that destined to become the alumina powders such as those that we supply begin to take very different routes.