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Lhoist UK produces Neutralac SLS45 high strength liquid lime designed for treating acidic effluents of all types. Neutralac SLS45 is stronger than any other liquid lime and comparable to 47% Caustic Soda solution. Neutralac SLS45 is more fluid than any other liquid lime and can be pumped and dosed easily. Neutralac SLS45 is more reactive than any other liquid lime and in practice is as fast reacting as Caustic Soda solutions. Patented manufacturing technology gives Neutralac SLS45 a highly stable, low settling formula. For more details contact Derek Thompson


Lhoist UK Ltd
SK17 0EL


Neutralac SLS45

Since its introduction to the UK market in 2009, Neutralac SLS45 has been able to secure its position as an effective alkali reagent that is superior to other liquid lime products.

Through its use within the metals processing and food industry, it has proven itself to be a safe alternative to caustic soda, whilst matching its performance with regards to reactivity, and showing improvements in its precipitation characteristics.

Developed and manufactured by Lhoist UK Ltd, Neutralac® SLS45 is a versatile liquid lime that has also seen success in wastewater and sludge treatment plants on continental Europe and most recently in the UK that deal with:

  • Stabilization of pH
  • Septic sludge
  • Thickening
  • Digestion
  • Dewatering

  • Neutralac® SLS45 is a ready-to-use liquid lime suspension that contains 45% Ca(OH)2 solids by weight. Its patented manufacturing process however allows this concentrated reagent to be delivered at a viscosity below 300 Centipoise (CPs), its sub micron particle size makes it more reactive (KIWA T90 < 5sec) and patented production technology allows a more fluid reagent than any other liquid lime.

    Neutralac® SLS45 gives the user a highly stable, low settling reagent for convenient integration into existing pumping and dosing systems.

    Most recently two sites for Scottish Water in North East Scotland have used Neutralac® SLS45 to adjust the pH of sewage sludge before treatment in their anaerobic digesters.

    At Inverness the quality of the delivered sludge varies significantly, and Neutralac® SLS45 has proven to be proficient at increasing the pH of the incoming acidic sludge to between pH 6.2-6.5.

    Stored currently on site in IBCs, regular 250l dosing per tanker of sludge is enough to take the sludge out of the 'septic' range and into a more acceptable condition for treatment.

    This pretreatment has effectively processed the sludge to yield a better quality feed for the digesters which gives a more improved and stable operation and has prevented the highly undesirable 'burping' of the digesters.

    At Montrose WWTW Neutralac® SLS45 is dosed into tankers before transportation to digesters offsite, Lhoist UK has installed IBC storage and metered dosing system on site and provided technical support during installation and set up. A lower dose of Neutralac® SLS45 accurately adjusts to between pH 7.0 - 8.0 from levels that can be as low as pH5.5.

    Neutralac® SLS45 can also be used to sterilize sludge prior to dewatering, as an effective method of achieving an 'enhanced treated' sludge suitable for agricultural use, trials at East Calder STW proved that the pathogen reduction is substantial and brings the sludge into compliance with 'enhanced treated' regulations, tests showed that a pH in excess of 11.5 was possible, way beyond the level needed for complete sanitization of the sludge.

    Further work suggests that the dry solids content of the sludge after dewatering is improved significantly.

    In other tests liquid lime dosing is reported to either eliminate or dramatically reduce H2S production with a corresponding reduction in sludge odour.

    With a processing plant and quarry located near Buxton, Derbyshire, Neutralac® SLS45 is produced on demand and sold through Lhoist UK and the UK's main chemical distributors, which guarantees a secured supply that is always available at predictable prices.

    For further information on the examples mentioned and on other case studies, as well as Neutralac® SLS45 in general, please do not hesitate to contact Derek Thompson, Product Manager, Lhoist UK Ltd, 01298 768670 email derek.thompson@lhoist.com

    For further information please email Lhoist Uk Ltd

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