No abstract

This research work centered on the determination of Liberation Size and Enrichment of EnyigbaLead Ore in Ebonyi state, Nigeria. The study reviews the fundamental operations in mineral processing i.e. the comminution process for the release and liberation of the valuable minerals particles from the ore association, and the eventual separation and concentration of the valuables from the gangue. The ore was pulverized, sieved to liberation size and beneficiated. The mesh of grind was found to be 189 µm, and the liberation size was established to be 63 µm sieve size having the highest percentage of lead of 15.1% then enriched to 69.8% by froth flotation method and was assessed by using x-ray fluorescence (XRF). The lead concentrate by weight was obtained to be 81.80%, confirmed being of high economic grade having surpassed 60% wt Pb element in an ore. It is hoped that this will enhance its development to meet both local and international demand for potential investment opportunities.

Tribometric evaluation of rubber (Hevea brasiliences) seed oil lubricant in upset forging was carried out. Upset forging was simulated with ring compression tests using Plasticine as model material and the rubber and reference oil samples as lubricant. The oils were applied to various die/ring surface combinations as they were compressed in the California Bearing Ratio (CBR) machine. Results show that friction factors for rubber seed oil ranging from µ=0.20 to µ = 0.577 compare favorably with the values for reference mineral base oil (0.29-0.42). Friction factors obtained from ring compression tests for the rubber seed oil are within the range of natural oil lubricants (groundnut oil; 0.072-0.5, palm oil;. 0.3, palm kernel oil; 0.084 and sheanut oil; 0.092). Rubber seed oil can therefore be used as a substitute for mineral base oils that are currently in use as lubricants in upset forging. Industrial organizations will derive immense benefit from this source of environment friendly, biodegradable and low toxicity oil lubricant.