Short answer: NO, these industries are not located in large population centres. They are located where their resources are: suitable clay for ceramics and brickworks, coal for brickworks and steel production, limestone for cement making. These are not necessarily where people are living, but even if you discovered a massive coal deposit under a city the cost of resuming all the private houses would be prohibitive, not to mention all the political problems. These waste heat proposals also ignore the costs of installing all the piping necessary to heat domestic housing, all for less than 6 months a year. In the remainder of the year you'll still have to vent the waste heat.
I see you still subscribe to the overpopulation canard. Back in 1984 I was doing some analysis on resource intensity in developed and developing economies, which involved looking up population figures. I was struck by the fact that ALL of the Western European countries had essentially ZERO population growth - without immigration they would have had negative population growth. That's true for every developed country - the underlying fertility rate is below replacement. Developed countries that do have higher rates of population growth - USA, Canada, Australia - do so due to higher immigration because not only do immigrants directly add to population but they also tend to be in their childbearing years. Without the immigrants they would also have negative population growth. That same process is ongoing in the developing world, as the population's income grows they have smaller families. This is conveniently ignored by the eco-warriors whose underlying aim is to keep the people of developing countries desperately poor in the name of their great god The Environment.
The truth that the eco-warriors don't want you to hear is that overwhelmingly the environment is getting better, not worse. Buildings and monuments in Britain that were black from decades of coal burning domestic fires are now clean, London no longer suffers from its deadly peasouper fogs. The rivers in the UK are cleaner than 100 years ago. Same goes for all the other developed countries. That environmental cleanup will also happen in India and China as their people become wealthier. As for the so-called "climate crisis" how can there be a crisis if there hasn't been any discernible warming trend in the last 20+ years? Have you noticed that we no longer hear about "global warming", it's now "climate change". Well the climate is always changing in a cyclic fashion, as anyone that examined the records of 20th Century temperatures can attest.
I don't want this thread to divert into an environment wrangle. If you wish to continue the debate please message me directly.