We create our "quicklime / calcium oxide", only from the purest limestone. After selection and washing, the  limestone is calcinated with sulphur-free gas, resulting in "quicklime / calcium oxide", which is then finely ground.

"Dry mortar" is won by hydrating the "quicklime / calcium oxide" in our hydration facilities, which converts it into crystallized calcium hydroxide (Ca(OH)2).

After calcination, the "quicklime / calcium oxide" leaves the industrial production process to undergo a traditional slaking process (mixed with water). The end product of slaking is milk of lime (aqueous slurry of calcium hydroxide), which is then in sealed in lime pits (currently, we store our milk of lime for up to 10 years).

Our minimum gauging / slaking period is three months.

The advantage of this gauging / soaking period becomes obivous during the application of the end product. Old soaked lime putty has a higher opacity, better water resistance and rubs off less.

NOTE:

The purity of the limestone, the calcination (850-900° C) with sulphur-free gas, the quenching process and the gauging / soaking period are the basis for creating high quality lime paste. Furthermore, the formation of large crystal plates takes place during these processes. These crystals improve the cohesion and light reflection of the lime paste.

Application / Uses:

Until the early 1970's, Lime putty was used for the production of plaster and mortar. In recent years, construction-methods and materials have been developed, that enable a faster and more efficient construction. Natural construction materials where often replaced by chemical and/or synthetic materials. The effects that these modern materials might have on the well being of the inhabitants, where hardly considered. Construction biologists warn that numerous ailments are either the direct result or are entailed by the use of such materials (i.e. mould).

Apart from classical uses of lime putty as plaster and mortar, it can also be used to produce lime paint and whitewash. In construction, lime mortar is appreciated for its latency and ease of application.

Today, construction companies and home-owners call for the use of biologically and physically sound construction materials. Lime products are synonymous for healthy living. Beside that, lime also helps to extend the lifespan of the building substance (especially the indoor and outdoor paint base benefits from the use of lime products). Whether it is used in construction, renovation or sanitation of buildings, limestone not only has an extreme longevity as construction material, but it also leads to a higher standard of living and well-being for the buildings inhabitants.
Another benefit from lime paints is their water permeability which enables walls to dry faster.
Furthermore, many monumental offices prescribe the use of lime putty in the restoration of historical buildings.

The applications of lime putty are numerous. They are safe and therefore also recommended.

The Qualities of Lime Products:

Applying lime paints on lime plaster is a perfect solution. Lime paints allow steam and moisture to escape from the walls, which keeps the underlying layers health, and fresh lime mortar is a great carbonatisator. Lime paint creates homogeneous relationships with the underlying plaster which it fossilizes (carbonates), thereby becoming insoluble in water.
A common argument against the use of lime products is that they have a low chemical tolerance. The main advantage of lime products however lies in lime's ability to neutralize acids and bases as superficial precipitations, preventing negative effects on the underlying plaster and mortar.
Experts speak of a so-called "sacrificial-layer". Lime paints might weather faster than dispersion or silicate paints, but multiple coatings will reduce or eliminate surface tension and seals.

Unlike film-forming paints like dispersion, glue, acrylic or silicate paints, the low vapour resistance and the respiratory activity of the underlying layers is maintained by the use of Lime paints. The cloudy appearance, especially in colours with high pigmentation, is typical of limestone façades and should be discussed in advance. For the best results, one should apply several thin layers, making it more time consuming, but the quoted benefits are worth the extra effort.

Slaking Timetable:

For high-quality plasters and mortar:
minimum slaking period of 3 months

For slurries, lime paints & colours:
1 to 3 year slaking period

For Fresco Paintings (must meet the highest demands):
6 year slaking period

We also have limestone that has undergone a 8 to 10 year slaking period for special requirements.

Dullinger lime products are available in all colours.

Interesting Facts about Limestone:

The use of lime putty as a building material has withstood the test of time; proving itself time and time again over the centuries and even today due to it's durability, and it's economic and ecological factors. We are committed to sustainability, and its is more important now than ever to choose resources that are readily available and also enviromentally friendly. From the extraction thought to the application, limestone undergoes and interesting life cycle:

Limestone is:

• extracted
• calcinated (burnt)
• hydrated
• processed and then converted back to limestone

Our product philosophy is based on maintaining high quality, creating products that function as you expect them to and a creating designs today that is are convincing tomorrow.

The Limestone Life-Cycle:

The limestone life-cycle represents how calcium carbonate (limestone) is turned into calcium hydroxide (lime putty) and then back to calcium carbonate.

The first step, is the extraction of CaCO3 (calcium carbonate), which consists to 95%
of calcium, carbon and oxygen.

In the second step, the crushed limestone is calcinated (burnt) at 850-900° C in a kiln. During the calcination process, carbon dioxide is released, resulting in the conversion from limestone to quicklime or burnt lime. The quicklime is then hydrated with water under a steady stiring process. The end product of this process is milk of lime, a aqueous slurry of calcium hydroxide. During this process the lime expands 2 or 3 times in volume and also begins to cook. Once the calcination and hydration processes are complete, the finished milk of lime is then pumped into lime pits where it remains for a slaking period where it turns into lime putty.

We store our lime putty for at least 3 months for the production of mortar, or between
1 and 6 years for high-grade limestone paint. This storage or slaking process results in denser and finer lime putty; old lime for example has a higher opacity than young lime putty.

In the next step, different aggregates are added depending on what product will be made out of the lime putty, or it is simply used as a base colour by mixing it with water (find out more under the headline "Lime Paint").
After the lime putty has been applied during construction, it once again absorbs carbon dioxide and solidifies. Lime putty is therefore a so-called air-mortar. At the end of the limestone life-cycle, the lime putty ends as it began, as calcium carbonate.