Abstract: A process is provided for preparing ammonium metavanadate from the combustion ashes resulting from the combustion of petroleum fuels in a boiler by using the ammonium sulfate and vanadium components in the combustion ash. Water is added to the combustion ash to form a slurry. The solids are removed from the slurry. Ammonia and an oxidizing gas, such as air, oxygen or ozone, are added to the aqueous solution obtained from the slurry to oxidize the vanadium, thereby producing an aqueous solution containing ammonium metavanadate. The ammonium metavanadate is crystallized and recovered from the aqueous solution. Calcium hydroxide or calcium oxide is injected into the aqueous solution and reacts with the ammonium sulfate to produce gypsum and ammonia. This gypsum and ammonia containing solution is flowed down a packed column, where it is counter-currently contacted with air or steam which strips the ammonia out of the solution.

Abstract: A method is provided for treating ashes from the combustion of petroleum fuels by mixing the combustion ashes with water to produce a slurry; injecting either calcium oxide or calcium hydroxide into the slurry and reacting the calcium oxide or calcium hydroxide with the ammonium sulfate within the ashes to produce a slurry containing gypsum and ammonia; flowing the slurry containing gypsum and ammonia down from the top portion of packed column and air or steam up from the bottom portion of the packed column so that the air or steam strips the ammonia from the gypsum slurry; and separating the gypsum from the resulting ammonia-free slurry using a solid/liquid separator.

Abstract: Comprises a mobile network exchange and a fixed network exchange in a composite communications network comprising a mobile network and a fixed network, or an integrated exchange in an integrated communications network, and a database which is accessed in common by the above-mentioned exchanges, and the above-mentioned exchanges call all or some of the terminals of groups comprising a combination of mobile terminals and fixed terminals, in accordance with the group data, or perform terminal change-over between the mobile terminals and the group terminals, in accordance with the above-mentioned group data.

Abstract: A system for selecting a called subscriber is provided in a telephone switching network for selecting a called subscriber from a plurality of called subscribers who desire to be selected and has a memory for registering identifying information on called subscribers, such as telephone numbers and passwords, in a table arranging the identifying information in the order of count numbers, and a selector for selecting a called subscriber from the called subscribers registered in the memory by a selecting subscriber who makes a call to the network for starting count in a counter provided in a processor and sends a stop signal to the network for stopping the count and producing a counted number for selecting the called subscriber.