Refractory materials with organic binders

Abstract

The use of organic products as binders makes it possible to eliminate water from the composition of the mixture, which permits a reduction in the drying time of the refractory lining of various metallurgical equipment* [i]. A feature of the use of organic substances is the fact that in firing they burn off, leaving a strong carbon formation, which possesses the property of not being wetted by molten metal [2]. Materials with such binders may be used for packing the joints between refractory parts in assembly of bottompouring assemblies t [i, 3], and also as ramming compounds [4] or guniting compounds [5]. In the general case their composition includes a refractory filler, an addition (organic or inorganic), and a binder. Depending upon the purpose, fibrous, carbon, or sintering materials may be used as the additions, and as the binder the greatest variety of organic products of petroleum distillation, thermally active and thermoplastic resin, and various cements* may be used [6].The authors of this article have prepared and investigated mixtures based on chamotte and magnesite with various contents (8-42%) of liquid phenol--formaldehyde resin (PFR) as the binder. The compositions of the materials were varied by the addition of scale, asbestos, and technical-grade carbon.The materials were prepared by careful mixing of finely ground (finer than 0.i mm fraction) refractory filler, addition, and binder. The prepared mixture of the components was poured into metal molds with a diameter of 0.035 m and a height of 0.05 m, packed using a Teflon cushion, and fired in the molds under a layer of coke breeze for 2 h at 1000~ The compositions of the materials are presented in Table i, and the results of laboratory tests are presented in Table 2.The addition of asbestos increases the mechanical strength of the samples, but causes practically no change in their gas permeability and density. The addition of iron scale causes a decrease in the compressive strength and refractoriness. With the addition of technical-grade carbon and the presnece of the refractory filler and asbestos, the service characteristics of the material are also poorer. The Ch-i and M-3 materials were selected for further tests.The samples were prepared from materials whose grain size composition is shown in Table 3. The resin and solvent content in the Ch-i material was 16% and in the M-3 material it was 12.5%, and the resin content after evaporation of the solvent was II and 8.5%, respectively.The samples were pressed at a pressure of 25-30 MPa, dried at 100~ for 12 h, and fired under a layer of coke breeze at 400, 800, and 1000~

Επίδραση Των Συνθηκών Παραγωγής Στις Ιδιότητες Πυρίμαχων Υλικών

“…Οι εφαρμογές των καμίνων περιλαμβάνουν περιπτώσεις από πρωτεύουσα τήξη μετάλλων έως θερμική κατεργασία υλικών, παραγωγή και επεξεργασία υάλου, παρασκευή κεραμικών εξαρτημάτων, καθώς και διάφορες μορφές χημικής επεξεργασίας και δοκιμών [24,[63][64][65].…”