Lead-acid tubular plates-using the wrong strength acid can put your company in a pickle

摘要

Dear Dr Mike: My name is Andy.I am the production manager of a lead-acid battery manufacturer making mostly traction batteries.These are 2V cells,6V and 12V monoblocs using both tubular and flat plate designs.We produce around three million cells and batteries per annum for mostly industrial deep cycle applications.Last year,we wanted to reduce the cycle time for making tubular plates.One of the measures was to reduce the acid pickling time after the plates are dry powder filled.For this we use a grey leady oxide which contains around 22% of free lead.After filling,the plates are pickled by dropping them into vats containing dilute 1.025 SG sulfuric acid for 24 hours.Six months ago,we had just begun running two shifts for plate production,which meant reducing the pickling time to six hours.In order to do this,we increased the acid SG to 1.25 SG to speed up the reaction.Figs 1 and 2 show the plates immediately after dry filling and then afterthe pickling process respectively.