The Gemara said that they would use a silver shovel everyday but on Yom Kippur they'd use a golden shovel. The reason why they would usaully use a silver one was because we don't waste Jew's money. But didn't we say before, "Ain Uniyos Bemakom Ushiros, We don't have any thing poor in a place of riches?
According to the Ritva, Ein Aniyus applies only as long as the gold will not become wasted and lost. In the case of the shovel, the gold will not remain to adorn the Mikdash, but will become lost through the shovel's use. See also Turei Even to Rosh Hashanah 27a who makes a similar point.
Your question may also be asked on the Gemara's statement (39a) that the Kalpi was not made of gold because of Chasah Torah Al Memonam Shel Yisrael. The Ritva there addresses that question and answers that the Kalpi itself was not really part of the Avodah, was only used once a year and was not mid'Oraisa.
Best wishes,
Mordecai Kornfeld
Dear Aron,
Thanks for your question. I would suggest that having a silver shovel complies with the rule "Ain Aniyus be'Makom Ashirus". The Gemara in Tamid (31b) asks why they used tables made from marble, since "Ain Aniyus be'Makom Ashirus". They should have used either gold or silver tables. Evidently, silver is not considered Aniyus.
Kol tuv.
Y. Landy