Metal Bulletin is proposing to adjust the normalisation ranges for its 38% Mn and 44% Mn manganese ore indices to ensure the two prices continue to gain the maximum possible liquidity.

The aim of the planned changes is to better reflect and capture the different material entering the manganese ore spot market.

The proposed changes only affect the normalization ranges for the two indices and will allow for larger volumes of spot material to be considered in the index calculation.

The base specification of the indices will stay unchanged.

Both changes are being made to include material being traded in the spot market.

For MBMnOI44 (44% material), we are proposing to increase the maximum silica content to 14% from 12%. The base remains unchanged at 4% silica content.

For MBMnOI38 (38% material), we are proposing to decrease the minimum manganese content to 36% from 37%. The base remains unchanged at 38%.

All other aspects of the two specifications remain unchanged.

For comments and queries please contact Alex Harrison ( by Friday September 27 2013, 12pm London time.

For full details of the manganese ore specifications, please click here.