CWR 154/2023 Raw Materials – Feldspars for glazed porcelain stoneware

CWR 154/2023 Raw Materials – Feldspars for glazed porcelain stoneware

The ceramic market is one of the main businesses in which Minerali Industriali has always operated; the 3.3 million tonnes sold in 2023 by the company include a vast range of sodium, sodium-magnesium, sodium-potassium and potassium-sodium feldspars suitable for the production of glazed porcelain stoneware.

Minerali Industriali caters for the needs of the Italian ceramic industry through its operations at three main sites in Piedmont: Boca (Novara), Verbania and Brusnengo (Biella).

The Boca mine produces Rhyolite S1, a natural potassium feldspar that is processed directly in the adjacent crushing and screening plant. Thanks to its high potassium oxide content and complete absence of carbonates, sulphur and oxidisable substances, Rhyolite S1 is an ideal choice for glazed porcelain stoneware formulations, especially for extra-thick sizes (>20 mm). Precise geological mapping and constant onsite blending ensure the consistency of the characteristics and quality of the finished product.

The recent introduction of RIO-SF30, a new product deriving from the synergy between the two production sites in Verbania and Boca, testifies to Minerali Industriali’s longstanding commitment to innovation. Due to its high fusibility, RIO-SF30 is particularly suitable for rapid firing cycles in the production of glazed porcelain tiles.

The production unit in Verbania epitomises Minerali Industriali’s commitment to the circular economy. Adopting a mineral treatment process that begins with waste originating from the processing of Montorfano white granite and Baveno pink granite, the group has been producing F60-30 potassium-sodium feldspar at this site for 30 years, making it the first pioneering example of mining waste recovery. Obtained by crushing, grinding, drying and magnetic separation of granite from Lake Maggiore, it is an ideal feldspar for glazed tiles with light-coloured bodies due to the presence of alkalis with a low chromophore content.

Minerali Industriali’s activities also extend to Brusnengo in the eastern area of the province of Biella, where the Group’s wholly-owned subsidiary Sasil operates. Sasil is a leading player in the field of industrial waste recovery and specialises in the processing of glass scrap. It also has feldspathic sand quarries in the municipalities of Curino and Masserano (province of Biella) from which quartz and feldspar for the glass, ceramics and sanitary-ware industries are obtained. Sasil produces Feldspar LC, an extremely pure potassium feldspar free of carbonates, sulphur and oxidisable substances, by carefully washing the feldspathic sands to reduce the chromophore content.

In addition to its longstanding operations of extracting, processing and selling domestic raw materials, Minerali Industriali has also invested over the years in geological and mining research outside Italy to identify the best raw materials available for ceramics, while at the same time starting a major trading business to offer the Italian market a wider range of products.

Following its investments in analysis laboratories in Turkey, for several years now the company has been importing high-quality sodium-potassium feldspars such as feldspar B1001, guaranteeing the high quality standards required for the finest Italian ceramic tile production.

Through its research efforts and investments in innovation, the company has cemented its position as a leading supplier of raw materials for the production of high-quality technical and glazed porcelain stoneware, while at the same time striving to reduce its environmental impact and improve the circularity of its production processes.

Read the article online on the Ceramic World Review