JOHANNESBURG, May 19 (Reuters) - South Africa has set higher import duties on certain steel products, ranging from 10% to 30%, to defend the struggling industry in the face of weak demand and rising imports led by China.

ArcelorMittal South Africa (ACLJ.J), opens new tab and others have shut some mills and the country's International Trade Administration Commission (ITAC) last year recommended that the government take emergency action to defend the sector, proposing import duties starting at 10% on steel products.

The duties announced in the government notice dated May 15 will apply to products such as flat-rolled iron or non-alloy steel, as well as bars, rods, tubes and pipes. Previously, South Africa applied tariffs of zero to up to 15% on these products.

"We are ‌hoping that this decision will provide the local industry necessary space to adjust in a manner that allows them to invest in their capability," ITAC Chief Commissioner Ayabonga Cawe said on Tuesday.

Tariff rebates for processors using products such as heavy structural steel and flat steel used in electronics have also been adjusted, Cawe said.

The tariff adjustments would not affect preferential treatment for certain geographies, he added.

Imports make up about 36% of South Africa's total steel consumption, with China accounting for 73% of imports, the South African Iron and Steel Institute says.

South Africa also imposed steep import duties on structural steel imports from China and Thailand in March after finding evidence of dumping.