Energy Consumption Points in Molybdenum Electrode Production and Efficiency Upgrades

A monthly electricity bill shows a single total, yet on the shop floor there are a dozen or more points of consumption. Break down the route from molybdenum powder to finished electrode and the energy is not evenly spread: sintering and forging take the largest share, pressing, annealing, machining and dust collection each take a portion, and air conditioning and cooling water run all year.

Mapping the points is the starting point for an upgrade. Furnace type, charge weight and shift pattern differ widely between companies, so the ranking cannot be copied, but the omissions are common to all.

Pressing and Sintering: How the Furnace Is Charged Affects Specific Consumption

Power in pressing comes mainly from the hydraulic station and die heating, with energy per unit of product tied to compact density and pressing tempo. Sintering is the concentrated consuming stage, where heating curve, hold time, charge weight and furnace fill factor together determine consumption per ton. In the same furnace, a light charge leaves the chamber partly empty and raises the share lost as heat, while an overloaded charge affects atmosphere uniformity. Running a few trials that vary charge weight and heating curve often reveals savings that carry no added risk. Compact dimensions are tied to the final electrode size, so unit weight and die can be fixed against the product specification pages before pressing.

Forging and Annealing: Insulation and Waste Heat

Forging furnaces draw heavily during heat-up and soaking, and the frequency of door opening and the pace of billet withdrawal directly affect heat loss. The waste heat of an annealing furnace is released during cooling, and if it is simply vented in one direction the heat is lost. Practical measures include adding insulation to the furnace body, shortening door-open time, and using the extracted hot air to preheat billets or heat the shop. Waste heat recovery should start with an assessment of air volume and temperature; at low temperature the heat exchanger efficiency is limited and the payback period lengthens.

The return on waste heat use depends on continuity. In batch production the heat comes intermittently, so the case for a storage system grows; in continuous production direct heat exchange is possible. Before deciding, log the exhaust temperature and flow for a week rather than estimating from nameplate data.

Auxiliary Systems Are Often Underestimated

• Dust collection and exhaust: fans run at full load for long periods with no control linked to the production rhythm.
• Cooling water: pump and cooling tower energy varies with season, and an over-tight water temperature setpoint raises consumption.
• Machining: standby losses of coolant pumps, lighting and the compressed air station.
• Air conditioning and dehumidification: where shop temperature and humidity requirements are tight, this share cannot be ignored.

These units are individually small but run for long hours, so the cumulative energy is significant. Submetering provides the evidence; without itemized data, the upgrade sequence tends to be set by impression.

How to Set the Upgrade Sequence

Metering first, operating adjustments second, equipment replacement last. Operating adjustments include shifting high-consumption operations off peak, consolidating furnace starts to the order rhythm, and aligning hold periods with the production plan. At equipment level, consider high-efficiency motors, variable frequency drives, heat exchange and recovery, and furnace insulation. Load shifting must take account of local tariff periods and delivery requirements, not the tariff alone. Maintenance is also an efficiency measure: ageing heating elements, cracked linings and detached pipe insulation all push specific consumption up slowly, and regular checks keep the loss small. Results of an upgrade also have to be verified with data: define a baseline period and a verification period and compare specific electricity consumption for the same product specification; where the order mix has changed substantially, apply an output correction so that a lighter order book is not mistaken for an efficiency gain.