In this paper, the synthesis of scheelite based environment-friendly inorganic yellow pigments was presented. The pigments of Bi1-x-yCaxZnyVO4-(x+y)/2 (x = ÷ , y = ÷ ) have been prepared by the evaporation to dryness from BiONO3, Ca(NO3), Zn(NO3) and NH4VO3. | Journal of Science and Technology 55 (1) (2017) 64-73 DOI: SYNTHESIS OF ENVIRONMENT-FRIENDLY (Bi, Ca, Zn)VO4 INORGANIC YELLOW PIGMENTS Tran Ngoc Tuyen*, Nguyen Duc Vu Quyen, Ho Van Minh Hai, Dang Xuan Tin, Dao Thi Phuong Mai Department of Chemistry, Hue University, College of Sciences, 77 Nguyen Hue Str., Hue city * Email: trntuyen@ Received: 20 April 2016; Accepted for publication: 18 August 2016 ABSTRACT In this paper, the synthesis of scheelite based environment-friendly inorganic yellow pigments was presented. The pigments of Bi1-x-yCaxZnyVO4-(x+y)/2 (x = ÷ , y = ÷ ) have been prepared by the evaporation to dryness from BiONO3, Ca(NO3), Zn(NO3) and NH4VO3. The obtained powders were characterized by Thermal Analysis (TG-DSC), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and CIE L*a*b* colour measurement. The results showed that the pigments calcinated at 650 oC for 6 hours with the heating rate of 5 possessed single phase of scheelite with good crystallinity. The yellow colour intensity was a function of the amount of calcium (II) and zinc (II) ions. The colour of sample was similar to the lemon yellow PbCrO4 (BASF1522) pigment made by Hangzhou Emperor Pigment Company (China). Keywords: yellow pigments, scheelite, environment-friendly inorganic pigments. 1. INTRODUCTION Inorganic pigments have been used extensively in many fields of porcelains, ceramic tiles, paints, inks, rubbers, plastics due to their high thermal stability, weather resistance and high hiding power. The factor creating the colour of pigments is the appearance of oxide, sulfide, phosphate of transition metals [1]. Among them, the yellow colour is usually prepared based on the appearance of compounds containing Pb, Cr, Cd, Se. For example, CdS is the main component of yellow powder or lemon yellow one widely-used is produced from PbCrO4. However, the toxicity of these metals could cause
