Liquid lime alleys caustic concerns
Since its introduction by Buxton Lime Industries over two years ago, Kalic Liquid Lime has proved to be an economic and safer alternative to caustic soda for drinking water and acidic effluent waste processing.
Kalic Liquid Lime is a unique product comprising an 18 per cent suspension of calcium hydroxide in water (Milk of Lime). The extremely small particles make for a stable suspension with a large surface area to give rapid reactivity and high efficiency for acid neutralisation and pH control. Kalic can also help protect tanks, vessels, valves and pipework from corrosion, so plant and machinery are less likely to be damaged. And its low freezing point (0ºC) significantly reduces the need for lagging and trace heating of pipework, pumps and tanks.
User friendliness, logistical and environmental factors, cost-effectiveness and rapid payback have all convinced Birds Eye Walls to switch to Liquid Lime in place of caustic soda at its Phoenix ice cream factory in Gloucester.
The hygiene process in a modern ice cream-making factory has its by-products: in this case, a cocktail of milk, vegetable oils and fats, plus a sprinkling of food particles, sugars, milk powders, flavourings, other ingredients and trace quantities of cleaning chemicals. The result, though non toxic, cannot be discharged into the environment without proper modification.
Environment officer at Walls, Paul Finch, explains: "The use of Kalic is one way by which we want to comply and seek continuous improvement within both ISO 14001 and the policy of our parent group, Unilever. Kalic has provided us with a positive environmental impact, as well as cost savings. We anticipate payback in less than a year as Kalic costs significantly less than bulk caustic soda and is also far more user-friendly."
The logistical problems of bulk storage also played an important consideration.
Caustic soda is not cheap to handle or store. It freezes at around 9ºC
and requires tanks which have to be lagged and heated for around nine months
of the year. It would have cost Walls more to store than Kalic, which freezes
at 0ºC, significantly reducing the need for lagging and trace heating of
pipework, pumps and tanks and is also easy to pump, handle and transport.