New Report, page-28

Might try to answer this one myself lol
Theres no overall Oz stats so I suppose its state by state
From the WA Dept of Mines:

CONSTRUCTIONMATERIALS
WA Financial Yr 2017-18

Aggregate t Quantity1,236,979 Value $ 34,886,656

Gravel t Quantity 155,354 Value $ 1,069,398

Rock t Quantity 267,629 Value $ 3,943,486

Sand t Quantity 4,085,649 Value $28,201,264

TOTALCONSTRUCTION MATERIALS Value $ 68,100,804

SILICA–SILICASAND

2016-17 t Quantity728,859 Value $ 20,364,867

2017-18 t Quantity974,445 Value $ 18,775,811

2010-11 t Quantity 430,363 Value $13,304,55

Theres not much info on Silica or sand at all.
Interesting that the t in 2017/18 is over double that of 2010/11 but the $value certainly isn't.. and in fact less than the previous year.

Its Financial year figures so the 2018-19 isn't available yet.