Metallurgical Molybdenum LCI Summary

The molybdenum products covered by the Metallurgical Mo LCI include:

  • technical grade molybdic oxide (tech oxide) in powder form,
  • tech oxide in briquette form, and
  • ferromolybdenum in chip form

The LCI is cradle-to-gate, which encompasses the processes that include extracting resources from the earth through the point at which the molybdenum products are ready for shipment to customers. Transportation of the finished product from the shipping dock to a customer is not accounted for, as downstream production stages, such as stainless steel or chemical manufacturing, capture this data in their own upstream material transportation data. Packaging of the products is included.

The system boundaries encompass five major unit processes, listed below and presented in the figure:

  1. Mining, including both the primary and byproduct industry;
  2. Concentration, also called milling;
  3. Roasting into tech oxide;
  4. Briquette production; and
  5. Ferromolybdenum production.

The 2008 update focused on increasing the molybdenum represented in the study, updating aged process data, and revisiting modeling decisions as necessary. Nine participating companies contributed data on 21 sites that include primary and byproduct mining and conversion facilities located in Europe, North America, and South America. Current process data on energy and materials consumed and environmental outputs were collected in detailed questionnaires. The molybdenum data represented 52% of the total molybdenum produced in the world and 75% of western world production (which includes all production with the exception of molybdenum from China, Mongolia, and CIS). This representation is an improvement from the 2001 study, in which 6 member companies contributed data that corresponded to approximately 65% of western world production. 

Metallurgical LCI Process

Aggregation of primary production data from the questionnaires included rigorous data checks, application of methodological rules that adhered to the ISO 14040 set of standards, calculation of weighted averages of facility data, and reporting of statistical information for each LCI flow monitored. The LCI models were built in the SimaPro LCA software.

The results, available upon request, are presented in terms of one kilogram of molybdenum in each product and are fully aggregated in terms of their total cradle-to-gate values. By themselves, the results have little meaning. However, when the LCI results are used in an application (e.g., as a raw material to stainless steel), the application and performance of molybdenum becomes meaningful and interpretable. 

Please note: the results of these LCI studies are not intended for use in comparing one molybdenum product to another. In fact, one should not compare any material on a per kg or pound basis unless the materials being compared have the exact same performance characteristics and can be replaced on a 1-1 ratio (this is rarely the case). Comparisons are meaningless – and inappropriate – unless proper functionality and performance characteristics are included in the systems compared, such as quantity and performance in an end product and the useful lifetime of that end product. Alternatives compared also should be reasonable and realistic.

Below are some results that look at the contribution of the three main unit process stages for tech oxide: mining, milling/concentration, and roasting. Most of the carbon dioxide and fuel energy in the cradle-to-gate tech oxide system come from the milling/concentration operations. Most of the sulfur dioxide comes from roasting, a pyrometallurgical process that converts the molybdenite concentrate into tech oxide.

Carbon Dioxide

Carbon Dioxide

OSx in Air

SOx in Air

Fuel Energy

Fuel Energy