* July imports from Australia climb 4.4 pct on-year to 7.47 mln T
* Mongolia cargoes up over 30 pct on-year, but off June record
* China has been clamping down on illegal mining at home (Recasts on imports from Australia, adds detail)
BEIJING, Aug 23 (Reuters) - Chinese coal imports from key supplier Australia chalked up year-on-year gains for the second straight month in July, customs data showed, as local output of the commodity eased amid a crackdown on illegal mining and pollution.
Cargoes from Australia rose 4.4 percent from July last year to 7.47 million tonnes, according to the data from the General Administration of Customs released on Wednesday.
Imports from neighboring Mongolia jumped over 30 percent in July from the year before to 2.26 million tonnes, the data showed, although that was below record levels struck in June.
Major producers from Mongolia are looking to boost shipments to China in the wake of a ban on coal purchases from North Korea and as China's largest producer Shenhua Energy closed two large pits near the Mongolian border.
Meanwhile, shipments from Indonesia dropped by nearly 9 percent to 3.03 million tonnes in July. Imports from Russia fell 1.7 percent to 1.64 million tonnes, the data showed.
China imposed a ban on coal shipments at small ports from July 1, along with more random checks on coal cargoes.
Looking forward, a warmer-than-usual winter has been forecast for southern China, potentially crimping appetite for coal.
The forward structure of the thermal futures curve shows investors are betting on prices peaking in October before falling steadily until August 2018.
China's coal production in July fell 4.5 percent from a month earlier to its lowest since October, according to government numbers released in mid-August.
(Reporting by Meng Meng and Beijing Monitoring Desk; Editing by Joseph Radford)