It is important to restate that the most significant influence on the properties of bleaching earths is the clay raw material. In addition to the product specification, all appropriate certification for the product must be in place. Relevant available certification includes:

Fulmont is provided in bulk road tankers, Big bags or 25 kg sacks. From raw clay through production to final customer delivery Fulmont is guaranteed every step of the way.

The overall in-use efficiency of bleaching earth is determined by several parameters, namely:

• Adsorption capacity
• Catalytic properties
• Ion exchange capacity
• Acid properties
• Particle size distribution.

Adsorption:

The high adsorption capacity of bleaching earths is their best-known property and adsorption capacity can be enhanced with acid treatment. The resultant increases in pore volume and surface area enhance the above parameters, giving the bleaching earth a high adsorption capacity for phosphatides, colouring pigments and trace metal impurities.

Catalytic properties:

The catalytic properties of the clay, are responsible for the destruction of peroxides, which increases oxidation stability of the refined oil

Particle size distribution & filtration:

The particle size distribution is of crucial importance: poor granulometry can lead to poor filtration rates and bleaching underperformance. It is thus essential to have tight control of particle size distribution in order to optimize overall bleaching efficiency. It is important to note that different oils and fats may require different bleaching earth characteristics. Fulmont provides an optimized particle size distribution.

A Fulmont fully acid-activated product ensures rapid filtration and may well exhibit bleaching activity 20 - 40% above that normally seen leading to a potential reduction in dosage requirements.

AMC supply a comprehensive range of bleaching earths for most applications required today.

Clay for acid activation is slurried with a pre-determined proportion of water plus acid. The slurry is heated to its boiling point for a few hours to achieve the desired end product quality. The clay is then water washed across a filter until the required residual acid level is reached. The clay is then dried and ground to specification.

Fulmont presents a moisture range of 8 to 12% to facilitate good bleachability and high filtration rates.

Bleaching clays should contain low levels of heavy metals, e.g. Pb, As, Cd, Hg, Fe, Cu. These metals are generally present in trace quantities [measured in ppm].

Fulmont activated bleaching clays have a bulk density of 0.5 - 0.65 g.cm³. The raw clay bulk density, before activation has a bulk density of 0.9 - 1.2 g.cm³.

4 key important factors

• The quality of the raw clay – Is the most important factor. High quality raw materials allow for the highest activation levels.
• The degree of acid activation – Is varied in accordance with clay quality and degree of activation required.
• Particle size distribution – Is critical in obtaining a fast filtration rate across the filter press and so ensure no bottle-necking.
• Moisture content – Should not be high since bridging may occur in the silo. Fulmont is optimized to 8 - 12%w/w.

Spent bleaching earth is disposed to:

• Landfill: Consult your local government for disposal criteria.
• Incineration: Whilst a more useful solution, it is far more costly. However, in some countries, where disposal to landfill has become increasingly difficult, the incineration route has become more popular.

Regeneration
The quality of the recovered clay is generally poor and too variable to be considered for commercial applications in the edible oils and fats industry.

Figure 3.1: Development of 17 Oils/Fats Production [million tonnes]

PRODUCTION OF OILS AND FATS

Over the last 50 years there have been significant changes to food production and processing with a trend away from animal fats towards [healthier] vegetable oils. The changes have been reflected by large scale production of oilseeds and improved processing technology.

Global production of vegetable oils and fats is currently of the order of
110 million tones per year, almost double the level of 20 years ago. This growth is expected to continue, notably in developing countries, driven by population increase as well as increasing personal disposable income. Regional demand is satisfied by a combination of:

• Crushing and processing of locally produced seeds
• Crushing and processing of imported seeds
• Processing of imported crude and RBD [“refined, bleached, deodorised”] oils.

The graph below shows production of the 17 principal oils and fats expressed as five-year averages over the periods 1976 - 2020 and 1981 - 2020 respectively.

The importance of the graph is that in the developed countries, for example Europe, shows relatively low growth - in line with Europe’s relatively stable population.

At the macro level the size of the market for bleaching earths is ultimately related to demographics. However, a large population and a large oil production do not necessarily mean a high level of refining activity - varying proportions of unrefined oils and fats are exported. The degree of refining activity depends on the oils and fats locally produced. The geographical spread of oil processing and consumption is also a function of crops grown locally and oil pricing.