Synthesis of Ultramarine from Reservoir Silts

Abstract

Ultramarine blue was synthesized by using reservoir silts as a major raw material to replace traditional kaolin clay. The reservoir silts were pretreated to collect the fines, in which the main mineral composition is illite clay. The fine part was mixed with sodium carbonate, sulfur, and activated carbon, and calcined at 800 • C for 8 h. The products were examined by X-ray powder diffraction (XRD) and a scanning electron microscope (SEM) to identify the mineral phases and particle morphology. The color characteristics were measured according to the CIELab system. Brilliant blue ultramarine powders were successfully synthesized with a chroma of 52.4, which is competitive with the commercial ultramarine.

Multi-Technique Diagnostic Analysis of Plasters and Mortars from the Church of the Annunciation (Tortorici, Sicily)

“…Noteworthy, the presence of iron in the corresponding area, as detected by XRF, can be reasonably due to the raw minerals used for the production of the synthetic ultramarine blue. Fe-bearing minerals, as, for instance, illite, can be used in the industrial process to produce the pigment [41]. There is no trace of pyrite, the common Fe-bearing mineral associated with the natural lapis lazuli.…”

Contemporary Methods for Production of Ultramarine

“…Charge Ultramarine is yielded not only from kaodine, but also from amorphous sodium alumosilicate, the mixture of sodium aluminate and silica, the mixture of amorphous alumina and silicon dioxide, as well as from the mixture of aluminuim-containing and siliferous waste after special treatment [15,16,17,18,19,20,21]. For example, while yielding UM-1 and UM-2 ultramarine grades, silicon is substituted with ferrosilicon dust, technical sodium aluminate is substituted with alkalineetched aluminium products, and while yielding UHK and UHK-A ultramarine grades, amorphous aluminium is substituted with dead aluminuim-containing catalyst.…”

Evidence for the catalytic properties of ultramarine pigment

“…The brilliant blue color of ultramarine pigment originates from the mineral lazurite ((Na,Ca) 8 (AlSiO 4 ) 6 (SO 4 ,OH, S,Cl) 2 ), which is present in lapis lazuli rock: a blue opaque semi-precious stone, historically found and mined in current Afghanistan [7]. Lazurite has the same crystal structure as the mineral sodalite, Na 8 [(AlSiO4) 6 ]Cl 2 , which is a feldspathoid group mineral with a zeolite structure [8], having so-called sodalite or ␤-cages (chemical formula (Al 3 Si 3 O 12 ) 3− ) as framework (Fig. 2a).…”