Hello,
The first possibility for such white particles in urine is kidney stones. You need to consult a urologist and get a urine examination and urine culture done along with an ultrasound kidney to confirm the diagnosis.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.