Preparation method of titanium-doped synthetic quartz sand

The invention relates to a preparation method of titanium-doped synthetic quartz sand, and belongs to the technical field of quartz glass manufacturing. The method comprises the following steps: gasifying a high-purity silicon-containing chemical and a titanium-containing chemical, carrying out chemical vapor deposition to obtain silicon-titanium mixed particles, carrying out spray drying granulation to obtain uniformly-mixed silicon-titanium doped large particles, carrying out heat treatment to obtain titanium-doped synthetic quartz sand, melting the titanium-doped synthetic sand in hydrogen-oxygen flame by a gas refining method, and carrying out sintering to obtain the titanium-doped quartz sand. The large-size bubble-free ultralow-expansion quartz glass ingot is obtained. According to the invention, the pollution of metal impurities except titanium caused by using natural quartz sand as a raw material is avoided, the high requirements of sintering of a titanium-containing silicon dioxide preform on equipme