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A Brief History Of Hydration Plants

Published by , Deputy Editor
World Cement,

QualiCal is proud to be a team of people that, 20 years ago, promoted QualiCUBE MODULAR solutions, marking a milestone in the design of compact plug & play solutions for hydration plants. 20 years ago at Kalk Fabrik Netstal (KFN) in Switzerland – where QualiCal’s first turnkey hydration plant had just been put into operation – the company was using an approach of continual innovation to help develop a new step forward.

The QualiCal modular solution.

At that time, an investigation of standard slaking plants available on the market had shown that suppliers’ experience in slaking highly reactive quicklime was somewhat lacking, and that few could offer a suitable plant without reservations.

Design characteristics

Since that first application, one of the competitive advantages of QualiCal solution was its compact layout, which was made possible by two novel technical developments from the company’s founder Mr. Gian Mario Cella. The SPYDRO moisturiser, with an integrated side bag filter, allowed a very compact hydrating machine, protecting the filter bags against the risk of burns.

The SUSep air classifier, fed from the bottom, also avoids additional bucket elevators between the hydrator and classification circuits. These two key features allowed for a hydration plant that was one-third the size of a typical design.

The overall design and the units selected alleviated the size problem: conventional slaking plants required up to 30% more floor area and were 60% taller. Consequently, the space needed for a plant with the same capacity would be twice as high. The QualiCal hydrating plant’s advantageous dimensions make it suitable for installation in confined locations. Its design features are novel regarding the slaking plant with dedusting on the side as well as hydrate preparation where air conveying replaces a bucket conveyor. In addition, this hydrator is able to handle and produce the highest fine hydrated lime rate, including in the case of highly reactive quicklime produced by PRF-twin shaft vertical kilns.

Prior to the development of the QualiCUBE design, construction work had been delayed by heavy snowfall and a cold Swiss winter.

Further developments

Despite the positive results achieved by this solution, the project execution was very hard both for the customer and the QualiCal team. The construction work was delayed by the heavy snowfall and a cold Swiss winter that year, and erection was heavily affected by the heavy winter conditions.

Learning from this experience, the company moved its engineering efforts towards a more compact solution, that could also be fully mechanically and electrically pre-assembled in a workshop, ready for installation.

In 2001, at the request of NUTARELLI, an initial prototype of the so-called ‘QualiCUBE_1 classification module’ was realised and successfully commissioned.

A modular solution

QualiCal developed a unique and original design, providing a full series of plug & play compact QualiCUBE modular solutions for quicklime hydration, hydrated lime classification and grinding and lime sizing.

The success of this idea allowed the company to secure more than 50 orders for the modular systems – with a capacities ranging from 5 – 30 tph, in Europe, Asia, Africa, North America.

Texas case study

Lhoist North America recently awarded QualiCal with a contract for the realisation of a hydration and lime classification plant.

The plant, to be installed at the New Braunfels facility in Texas, will have a capacity of 30 tph and will be realised using state-of-the-art QualiCUBE systems.

This award provides confirmation that the path taken by QualiCal was in line with the needs & expectations of lime producers.

QualiCUBE_1 Classification Module prototype manufactured at the QualiCal Workshop.


QualiCal is a mirror of its employees and is moved by the desire to grow by promoting and realising new ideas. As a supplier of technical and technological solutions, the company has always had the good fortune and the freedom to work with its role being dictated more by the responsibility to promote progress and innovation, than purely financial concerns.

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