The first flow diagram illustrates the process of glass container production, and the second
diagram shows steps in the process of recycling used glass. ! !
We can see that glass is made using three main raw materials, and that the manufacturing process
consists of four distinct stages. It requires five steps to turn used glass into new glass products. ! !
At the first stage in the production of glass, sand, soda ash, limestone and other chemicals are
mixed together. Next, this mixture is heated in a glass furnace at approximately 1500℃ to produce
molten glass. The molten glass can then be shaped, by blowing, to create the end products,
namely glass containers.
Glass recycling begins with the collection of used glass products. The collected glass is sorted
according to its colour, and then washed in order to remove any impurities. At the fourth stage of
recycling, the glass is crushed and melted, and the resulting molten glass can finally be moulded to
create new items. 
The  
first
 flow diagram illustrates the process of  
glass
 container production, and the second
diagram  
shows
 steps in the process of recycling  
used
  glass
. ! !
We can  
see
 that  
glass
  is made
 using three main raw materials, and that the manufacturing process
consists of four distinct stages. It requires five steps to turn  
used
  glass
 into new  
glass
 products. ! !
At the  
first
 stage in the production of  
glass
, sand, soda ash, limestone and other chemicals  
are
mixed
 together.  
Next
, this mixture  
is heated
 in a  
glass
 furnace at approximately 1500℃ to produce
molten  
glass
. The molten  
glass
 can then  
be shaped
, by blowing, to create the  
end
 products, 
namely
  glass
 containers.
Glass recycling  
begins
 with the collection of  
used
  glass
 products. The collected  
glass
  is sorted
according to its  
colour
, and then washed in order to remove any impurities. At the fourth stage of
recycling, the  
glass
  is crushed
 and melted, and the resulting molten  
glass
 can  
finally
 be  
moulded
 to
create new items.