Grinding and classifying installation for kieserite production
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Monte Kali near Wintershall, a K+S KALI GmbH site
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Project Manager W. Vogt, K+S GmbH, and...
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3 Installation of the two cyclones
K+S KALI GmbH, with production sites in Germany (Fig. 1) and France, specializes in the extraction, processing and utilization of potassium and magnesium salts and extracts 8.7 million t crude salt every year at the site near Wintershall. From kieserite, the company produces a sulphatic magnesium and sulphur fertilizer with 25 % water-soluble magnesium oxide and 20 % watersoluble sulphur. The main application is in combating chlorosis, a deficiency syndrome suffered by agricultural crops. Kieserite is approved for use in ecological farming.
In March 2007, Hosokawa Alpine received an order from K+S KALI to replace three old mills with one large, high-capacity turn-key grinding mill and classifier that can be run in 24-h operation to produce an annual output of 550 000 t kieserite with a fineness of 90 % < 90 µm. The supplied plant went into operation in January 2009. It comprises the largest Super Orion ball mill (Fig. 2) that Hosokawa Alpine has ever built: a wear-protected SO 400/500 steel ball mill with a weight of approx. 250 t, a motor power of 1 300 kW, 5.5 kV, equipped with sliding bearing system, slotted wall and neck journal discharge. The ball mill is operated in a closed circuit with a Stratoplex 1800 ASP air-swept classifier and two KAZ 2500 cyclones. The air circulation rate of the classifier is around 100 000 Bm³/h. The cyclones have a diameter of 2.5 m and height of 9.5 m and, like the classifier, are lined with hard metal (Fig. 3). The scope of supply included four bucket conveyors, each with a height of around 25 m, three troughed chain conveyors, each measuring 30 m in length, and a proportioning belt weigher with a width of 1 m. With a value < 1.5 mg/Bm³/h for the residual dust content verified and attested by TÜV-Sued, the dust collection system also included in the € 4-million contract ensures much better air purification than the residual dust content of < 10 mg/m³ specified by K+S.
The good cooperation, fast processing of the project and the results achieved with the supplied plant and with which the specified targets can be met have prompted K+S KALI to entrust Hosokawa Alpine with a new project: a plant for the production of kieserite at its Neuhof-Ellers site. For this application, Hosokawa Alpine has proposed the supply of a 1500 AWM table roller mill.
HOSOKAWA ALPINE AG, Augsburg (D), Dipl.-Ing Jörg Eisold,
Tel.: +49 821-5906-0, www.alpinehosokawa.com
